melinda B. | May 13, 2008 at 2:49 pm
Thank you for all the chemistry information.I am a 37 yr old and have a very poor math background in math and science but I am of average intelligence and hope to be able to learn them starting with basic algebra. I am trying not to let negative comments like “oh you needed to have learned math and science when you were a child”, “it’s too difficult to learn as an adult!”. Your articles have inspired me so please wish me luck!.
Mike Law | June 15, 2009 at 10:59 am
If you are even remotely interested in learning any new subject then you have all the intellect required. Learning does not end when we leave school; learning is a life long process. What does end when leaving school is getting credit for having a brain; also, less time is available to learn because most jobs are interested in our hands and not our brains. My background is not much different than yours, being a curious person, as you clearly are, what I did is start a self-study program. About.com is a good place to begin. I also like “The Cartoon Guide (many subjects) by Larry Gonick”
Gonick has a whole series of entertaining books and you can get an introduction to a subject in a short time. There are many other good introductory books and web sites. Good luck with your studies.
kyle | May 13, 2008 at 11:45 pm
I wanted to know why does the combination of Heet and boric acid make a fire turn green i saw it and im curious
azareal | May 14, 2008 at 12:25 pm
The green comes from the emission spectrum of heated boron. Heet is methanol… it makes a good fuel for green fire in part because it doesn’t contain sodium. Sodium has a bright yellow emission that would drown out the green color from the boric acid.
Chris | May 14, 2008 at 3:07 pm
Re your piece on Cherry Pit Toxicity.
I recently saw a recipe for cherry pit ice cream on a food blog, suggesting that cooking the ground inner pit (which is mixed with sugar) and added to the cream, which is heated to 180. The recipe calls for the inner part of 60 or so pits for one batch of ice cream. Thoughts?
JK | May 20, 2008 at 9:04 am
Dear Mrs. Helmenstine,
I’m currently a student in Chemistry AP, and I came about your About.com article on making ferrofluids.
One of the ingredients necessary in the article is oleic acid. I was wondering if using Canola Oil (57% oleic acid, but wikipedia says only 0.5%-2.5% is actual free acid) would work, or if 100% oleic acid is needed. Would the oleic acid still react with the ammonia?
Thank you very much for your time.
m | December 4, 2009 at 2:56 am
I’m also working on the ferrofluid and used flaxseed oil because it is the only thing they had at the healthfoodstore that even had oleic acid in it.
This did not work at all. And there oleic acid is nowhere to be found.
Maybe I will try the canola oil next and see what happens, but I have a feeling it is also going to fail.
what can you substitute for oleic acid?
Kay Morrison | May 20, 2008 at 9:17 pm
I am making a smoke bomb for science class and could not find the potassium nitrate. I have potassium chlorate and would like to know how much baking soda I should add to 1.5 cups potassium chlorate and 1 cup sugar. Do you cook this recipe or is the chlorate totally different?
mohamud | June 4, 2008 at 11:20 am
sister, i want to teach a chemistry can i have a cd”s of chemistry by vitual learning becouse i stay in somlia.
adam | June 7, 2008 at 4:51 pm
I am a cultural anthorpologist investigating the myth of red mercury in relation to alchemy and ancient beliefs and traditions. i have been surprised finding out that its related to terrorism as well.
i need to ask you to clearify to me whether there is any ancient red mercury used in ancient alchemy and modern red mercury used for other purposes might be related to terrorism….
a. el masri
sara karimi | June 16, 2008 at 9:37 am
Dear Mrs. Helmenstine
i need help beacause i have cancer and my mother is sick i dont have any money for visit ing doctor i dieing after3 month doctor said
i have 18 year old and i wish make crystal and get money for visitng doctor because my mom dont have money help me plz
qamar | June 16, 2008 at 1:50 pm
I am very inspired from you. I am very thankful to you for news letter. I m chemistry teacher and teach classes 11th and 12th.
May you more and more success in your life.
monk11 | April 27, 2010 at 1:34 am
Try learning to speak proper english Qamer before trying american students anything!
qamar | June 16, 2008 at 1:54 pm
we have hand pump in home and EC of water is 1200ppm, which is not good for drinking. Can you suggest some ways to make it portable.
Don Annival | April 27, 2010 at 1:40 am
Thr word is potable quamer not portable. Abd I see why you do not teach chenistry anymore, buy good luck with your blog.
Boris korey | June 18, 2008 at 5:04 pm
Dear Anne Since i discovered your webside, i enjoyed your lessons. I am a lover of chemistry and biology. Last week i took my entrance in a private university to start my courses in a medical department.
I will always read from your lessons and use them to review and improve my knowledge in my beloved topics.
I will apply your guides to become a good scientist.Thanks so much for your motivations.
Gregory H. Robinson | June 24, 2008 at 8:16 pm
I find it disappointing that in your listing of “famous black chemists” you note Mae Jameson (who is not even a chemist, but is a “retired mediccal doctor”), and mostly deceased chemists (save for one entry). I would refer you to Dr. Joseph Francisco (Perdue University) and Dr. Isiah Warner (Louisiana State University). Drs. Francisco and Warner certainly are “famous” and are successful practicing chemists.
Giovanni Danieli | June 30, 2008 at 11:36 pm
Dear Ms Anna Marie,
I am a simple teacher in upper school for chem. and biol. .
But a friend of mine asked me : ” Do You know how works the light” , I am sure, not the light, but the stick that emit flourescent light, the same You can buy at the Luna Parck.
So can You help me to give him an answer.
( I am sorry for my poor Enghlish.)
I wisch You all the best
sundar | July 6, 2008 at 5:52 pm
i want to make boric acid gel. at what temperature i should heat to get it. is any other method available other than heating boric acid powder?
elyfe | August 5, 2008 at 9:39 am
_your site is a nice site to have a reference…:)
_just like to ask if you have a book or workbook that you have published or have done…may i know the title..??
_thanks very much!
_have a good day ahead…:)
Mark O' Brien | August 7, 2008 at 8:59 pm
Hi, I am an Industrial Biochemistry student in Ireland, I have been getting your emails now for quite some time! They are very interesting! Thank you so much for putting the Chemistry & Biochemistry I learn into everyday perspective! I also wish to achieve Ph.D someday!
Rahul Bose | August 10, 2008 at 6:10 pm
I am a student from India studying in the IIT.
I was wondering if you could give me some information about p pi-p pi backbonding in Boron Triflouride(BF3).
I need the information ASAP. It would be very kind of you, if you could help.
Thanking you once again.
shiva shankar h d | September 9, 2008 at 12:41 pm
i was so inspired by your information.my spirit for doing my further study has been trippled.by your stright forward preeches.you are best advicer as well as best friend if you like.
20. Deborah J./September17,2008 at 12:42 pm | September 17, 2008 at 4:46 pm
DR Helmenstine I am a nursing student and I needed help learing chemistry and how to study for exams.
Wolaz | September 23, 2008 at 1:56 pm
locoliam | September 23, 2008 at 5:02 pm
Hi Dr. Helmenstine,
I saw your article “How To Make Resin Papier Mache Paste” on About.com. I’ve checked a number of sites and am confused as to where I would get the powdered resin glue. Craft stores do not seem to have the powdered version, and hardware stores have “polyester” or “plastic” resin glue in huge containers. Are they the same thing you refer to in your article?
While I’m bugging you with questions, can you tell me if the resin glue is non-toxic or biodegradable? I’m looking at a craft for second graders and they might drink from the waterproofed paper mache vases we’re looking to make. I don’t want anyone getting sick.
Thank you, in advance, for your time.
LK – email@example.com
Ryan | September 25, 2008 at 1:56 am
Dr. Helmenstine – I followed your instructions for a storm glass and it works to perfection.I wanted to ask you a question. All my friends want storm glasses now and I want to make them. However, I’m having trouble purchasing the amount of ethanol that I need. Could I substitute 95% pure grain alcohol – the kind purhcased in liquor stores? Thank you so much. I can be contacted at firstname.lastname@example.org
Frankie | October 24, 2008 at 10:56 pm
Oh, how I wish your site were around 30 years ago. I tried to create so many of your experiments myself without any resources as a child and it was always so frustrating. It is very satisfying to read about them all now as an adult. Thanks for your kind sharing of knowledge and humour.
david mcclellan | October 28, 2008 at 6:32 pm
In reply to a post on smoke pigments,
I am attempting to make smoke bombs I have followed these instructions http://chemistry.about.com/od/chemistryhowtoguide/a/coloredsmoke.htm except I did not add the dye, just the potassium sugar and baking soda. The concoction is not a smoke bomb, it is more of a flaming smoker thing. I am wondering is the dye an essential ingredient for the bomb to create smoke with out the flames? The other thing is when I add the baking soda to the mixture it poufs up, is this suppose to happen?
mohammad jalalian | October 31, 2008 at 1:31 pm
Dear prof.Helmenstine,I am a doctoral student in vienna,I would like contaction with you or your group,and I like known better you
Carlos Javier | November 4, 2008 at 6:41 pm
Hi Dr. Helmenstine, I’m an actual student of Biological and Chemical Scienes in the Facultad de Ciencias Biológicas UANL, in México.
I just wanted to congratulate you for your articles wich I found very interesting, specially the “Turning Lead into Gold” transmutation article, wich I found very informative, and your “home” chemistry experiments.
Hope to read news from you.
mathew | November 20, 2008 at 6:00 am
hmm… i was wondering about the reactions in storm glass… These are the importants facts that i am going to present in my class….. Do you have any idea of it?? Or else, can you tell me more about camphor so that i will know the storm glass better…. Please help me ….
PRIYANSHU | November 28, 2008 at 1:42 pm
your project ‘storm glass’ was very helpful to us.
Eddy Harris | December 7, 2008 at 2:23 am
Does any one knows how to make crispy tempura? What should I add to the mix to make it crispy? I tried baking soda but it did not make it crispy at all
Judy G | December 15, 2008 at 2:08 am
Hi Dr. Helmenstine,
I read your experiments and want to do them with my class, but I have no fume hood. I never see any reference to using a fume hood, but I still worry about fumes from some experiments. For example the dancing gummi bear. I’d love to try it but it appears to be releaseing copious amounts of “something” into the air. Is it safe without a fume hood? Are all your experiments safe without a fume hood since they do not specify this safety requirement?
Do you think you will ever release a book with all these interesting experiments in it?
Thaks for your help,
Richard | December 28, 2008 at 4:27 am
Hi there, can you tell me: when you light a safety match, what is it you smell, burning phosphorus or burning sulfur?
satalkar uday | January 2, 2009 at 4:31 am
Anne actually i also not known the exact full name of you but although i read your newsletter and i am very thankful to you that there is some person who inspiring me for doing me career in chemistry so thank you. your further motivation will help us in achieving the goal in chemistry.
Ray Lundin | January 11, 2009 at 9:09 pm
Dear Dr. Helmenstine,
I’m a gemologist and writing an article on gold. One part explains the gold in gold jewelry. Your article on gold alloys is the best I could find on the net. I would like your permission to print your chart on gold alloy composition in my article. The article is for the Rock & Gem Magazine. Thank you,
Carol V | January 14, 2009 at 1:07 pm
Dr Helmenstine, I found your info on a google as I am trying to find a chemist who may be interested in finding the new article concerning melamine only causing kidney stones in humans (unlike what we pet owners were told in 2007 that cyanuric acid was also necessary for kidney crystals/stones…there is a recent journal article which I have been unable to find…even an abstract…did not know if you had any advice as to how to find this…the article may reference to “how much” melamine alone is considered safe and was based on studying the children affected by the melamine milk nightmare in China…here is the journal that is referenced “International Journal of Clinical Chemistry and Diagnostic Laboratory Medicine” and here is the link to the Reuters news article..thanks..
mike | January 31, 2009 at 4:02 am
Great site! Always fun to refresh some chemistry concepts. The new economy presents much opportunity for those w basic scientific knowledge-especially cognitive reasoning skills for problem solving. Just look at alternative fuels(ethanol,fermentation processes,microbiology-just to mention one)Chemistry is import. to everyday life.
dony | January 31, 2009 at 1:45 pm
Hello mam…i m dony doing Ph.D…in chemistry…….i m a teacher in a institute and want to make the working models on chemistry, physics and biology topics so plz suggest the method and materials and the thorough procedure …as soon as possible bcoz the the last date of practicals of my students is 07 feb 2009… i m waiting.
vince | February 1, 2009 at 4:19 pm
I am a wrestling coach and am looking for better ways to disenfect my wrestling mats. I currently use bleach but was told it would be better to add vinegar. I know that mixing acid with bleach will produce chlorine gas. My question is at what quantities is this harmful. I currently use 2-3 oz. of bleach/gal of water to mop the mats. Would it hurt to add a small amount of vinegar?
Thanks for the help.
andrew kim | February 24, 2009 at 2:04 am
Hi, my name is Andrew Kim, and I attened to Harbour Pointe Middle School in Mukilteo, Washington. I am 7th grade in the Middle School
Thanks For giving up your time for me.
I am conducting a science fair project on the topic of finding the amount of vitamin C in different brands of Orange juice , and am in need of some expert advice.
Would you be willing to answer a question or two for me?
My investigative question is “What evidence indicates that the different brands of orange juice affects the amount of vitamin C?”
I know that titration is used to measure the amount of vitamin c in certain content. Can you explain how the titration is exactly done, and how it is useful to the community?
Also, I am sure there is a certain measurement to measure vitamin c, such as mg or ml. However, i am not sure of what measurement vitamin c is. Could you explain the measurement for me? (additional question relating to this question: Is there any mathematical procedure to find the measurement (amount) of vitamin c?)
Finally, I understand that stoichiometry is a key thing to learn when you’re finding the chemical amount of a content. However, as I looked up in the dictionary/encyclopedia/internet journal/magazine, the definition was stated very confusing/ ambiguous for me. All I could see was some random equations and way too complicated words. Can you please explain stoichiometry in an easier term?
Do you have any tips or suggestion that will make my science fair project successful?
Thank you for your time. If you happen to live near Mukilteo, Washington, you can come and view our science fair project on Thursday, June, 4th from 7~8:30pm in the HP gym.
sincerely, Andrew Kim
Dr. Salam | March 2, 2009 at 11:39 am
A prof. of physics, i see that you are mastering successfully so many topics in various fields, especially in chemistry, that very old/new science. My congratulation , keep on going
Salam, from Libya.
Dustin Palmer | March 6, 2009 at 4:04 am
is their any one that can perform a chemical lab test to find out if ” beryllium ” is present in my raw ore from my mine! I have conducted a home test and it show’s that beryllium is present, yet to find someone or a company that can perform a assay report on my raw earth material containing this element has me at a stand still. Any information would be greatly appriciated thanks:) DP
ltreddy | March 20, 2009 at 12:28 pm
great profile,all the best
Wes | April 13, 2009 at 4:26 am
I looked at the pictures of Hawaii’s Green Sand Beach and was amazed that the sand is clear like that and green! Its like… well… I’m not sure what its like! It looks like candy I suppose. I was wonder, with all that green sand, where is it wearing off from? Is it the cliff above it that someone was walking down past on the sand slope? It mentions something about using a ladder but I don’t see one in the picture. Or maybe its wearing off out in the ocean? I don’t know when I’d ever be able to go to Hawaii but that beach sounds really interesting! I have gone to a garnet mine in New York state where there were millions of little tiny red garnets mixed in with black sand. That has been The Most Interesting Sand I have ever seen so far! I know its kinda dorky but I think its interesting! XP
ALI RAZA | April 20, 2009 at 7:15 am
send me some information about chemistry.
Ted Burrett | April 22, 2009 at 7:03 am
If you ever want to see a reader’s feedback 🙂 , I rate this post for 4/5. Detailed info, but I just have to go to that damn yahoo to find the missed bits. Thanks, anyway!
casey | April 28, 2009 at 3:44 pm
I have been working with the fire coloring compounds that you have listed on your fire coloring tutorial. Cupric chloride is absolutely beautiful, and makes for some safe elaborations for different effects uses around the fire.
I had some simple questions that you may be able to help me with. With potassium Chloride -purple(I have in granular form), strontium chloride- red(lump form that I ground to a powder), and cupric sulfate – green(lump form that i pulverized), i don’t get very dramatic reactions, and haven’t really seen noticeable color. I am putting up to 1 cup into the fire at a time, giving ample time for the last to burn off before hand. I am not sure what the problem may be.
I am working with a standard sized campfire that is established and quite hot. Could it be that i may need to supply some kind of oxidizer or chloride to my compounds to enhance the reaction?
Any suggestions you can offer will help. Your information on this site has brought smiles to many many faces. Thanks.
BigPoiDog | May 5, 2009 at 3:19 pm
I’ve been meaning to thank you for posting information on the Kids Science Challenge (you tweeted this several months back) — I probably would not have known about it otherwise.
My son Gabriel (3rd grade) was a finalist in the competition (under the SETI topic) and won some really cool prizes. He’s been inspired by his success and has announced to the family that he will be scientist when he grows up — as well as a businessman and musician…ahem.
In any case, you may have set off a butterfly effect that will lead to…who knows where… 😉
BigPoiDog | May 5, 2009 at 3:31 pm
I went out and got my stump remover over the weekend…
Did I miss the follow up on ideas for home made pyrotechnics for the 4th of July?
Curiosity is killing this cat… 😉
Mark Pitkin | June 29, 2009 at 1:55 pm
I would like to make a reference in my paper to your article on “Rigor mortis”: http://chemistry.about.com/cs/biochemistry/a/aa061903a.htm.
Please advise, how the reference should look like.
Thank you in advance,
Mark Pitkin, Ph.D.
surabhi sumant. | July 10, 2009 at 10:05 am
I’m an eleventh grader frm india.I wanted more info on empiricals formula and i found it on about.com….thnx 4 u’r info….i also checked out u’r article on how to make crystals n loved it…i’ll b soon trying them….can u tell me how to make resin papier mache paste i missed that article n curiously want to know….thnx 4 u’r help!!!!Kindly reply……Bye n Take Care!!!!!!!!!!
Maria Pontiero | July 13, 2009 at 2:11 am
What are the implications of every reaction having an equilibrium controlled by kinetics?
ace | September 3, 2009 at 7:43 am
Lots of work for PhD students.
More seriously, the result in my experience is preferential reactions – two different reaction pathways might be possible, and you might think you know which is the more likely pathway/product because you’ve looked at the activation energies, but then the kinetics of that reaction might be much slower so you end up with the other… thereby leaving you with completely the wrong product.
Although the real answer is that not every reaction is controlled by kinetics, and there are arguments going on especially for nanoscale reactions as to whether you get kinetic or diffusion-controlled reactions. Fun stuff.
Global | July 27, 2009 at 9:43 pm
I love your projects
Michael Stuart | August 4, 2009 at 4:50 am
I’m a science teacher preparing for a science fair on 8/11/09.
I finally found stump remover in order to make the smoke bomb according to your instructions. Could you please let me know the chemical equation of this reaction?
KNO3 + C12H22O11 + O2? –> ???
Michael Stuart | August 9, 2009 at 1:17 am
I have 2 more reaction questions:
1. I learned of a reaction of vinegar with the Ca carbonate in eggshell. Is this the correct reaction?
CaCO3(s) + CH3COOH –> Ca2+(ion) + OH-(ion) + CO2(g) + CH3COO- (acetate ion)
2. We cooked sucrose until it left a black residue. Is this the reaction? C12H22O11 –> C(s) + H2O(g) ?
Matthew Wilson | August 20, 2009 at 4:05 am
I am a Bingo Manager for an Indian casino in California located about 1/2 mile from the Sacramento River and tons of farm land. My bingo hall seats close to 1000 people and has relatively easy access to the outdoors. Traffic in and out of the hall is abundant.
Naturally, this mean LOTS of mosquitos and flies. Although the flies are a nuisance, the mosquitos are the biggest problem. They are hardest to control. As we serve food in the hall, typical means of controlling these pests cannot be used (i.e. DEET sprays). However, after reading your article on “natural repellants,” I was curious if you have had any success in large rooms or auditoriums.
My thinking is that little candle dishes can be placed on the tables and various oils can be added to “repel” the mosquitos away from the guests.
Do you have any suggestions?
Thank you very much
azareal | August 20, 2009 at 1:10 pm
A lot of people use citronella candles as an insect repellent. However, some people are sensitive to the natural oils even as some are sensitive to the synthetic repellents.
Another option would be to use positive air pressure. Grocery stores and restaurants with outdoor seating use these blowers with great success. I don’t believe they are terribly expensive.
Brian Dolezal | September 1, 2009 at 7:13 pm
When doing calculaitons is it best to round significant figures with each step or to just round at the end of the problem?
ace | September 3, 2009 at 7:36 am
Always at the end of the problem. That’s the way I was taught, and if you work through a problem you will see that the more often you round, the more errors you introduce into each step. Keep as many figures in as you are able until the end of the calculations, and then ensure that the final answer is rounded to the appropriate number of significant figures.
ace | September 3, 2009 at 7:34 am
I tutor both secondary and tertiary chemistry. I spend hours working through lecture notes coming up with question sheets for my students. Your question sheets and worked examples for things such as C14 dating really help to spark a bit of interest! Thank you so much.
Alice | September 5, 2009 at 7:51 pm
I looked up your article about substituting for Baking Soda and I am thoroughly confused. What you said makes no sense-if I triple the amount of baking soda I am not getting rid of the baking soda but that’s what you said. Also what is tdp – is that supposed to stand for tsp? All I need is a substitute for baking soda –
Alice | September 5, 2009 at 7:52 pm
I forgot to check the notify me box – please notify me via e-mail
Annie | September 30, 2009 at 3:01 am
how can chemistry related to preventing the flood?
khazunghu paul | October 2, 2009 at 10:23 pm
i need to thank you with my open heart because you support us on your site God be with u.i am rwandese in cental africa with 25years iam student in natinal university of rwanda, sciences faculity and departement of chemistry that why i like chemistry very well i need to become proffessor like u; in general i use your site in laboratory rapport,to consulte your project ,and so on please be with God in your work to support you
ryan | January 1, 2010 at 8:58 pm
there is no god or gods so please stop wasting your energy thinking that there is.
E.MAHESH BABU | October 3, 2009 at 2:02 pm
Iam pursuing chemistry.Iam very thankful to give information and I INSPIRED from you
hooban | October 10, 2009 at 8:47 am
im work HSE in OIL & GAS com
i neeeeeeed to safety signs (type ,size ,colour
bakhshi arash | October 21, 2009 at 10:14 am
i want making cristal meth(bad)
Jasmine | October 28, 2009 at 2:28 am
i am using your experiment about changing the color of fire as my science fair experiment. It is very fun and I thankk you for providing me with enough information. I have one dilema though. Some of the colorants listed are not where you say they are. I would appreciate your help finding those colorants.
Jasmine | October 28, 2009 at 2:30 am
I am not doing the same exact experiment, but one similiar to it.
John Phillips | November 7, 2009 at 2:20 am
On two occasions I have seen a stalagmite form in the cat’s dish at temps of about -2C or close to. The first time the stalagmite was almost as large in diameter as a AAA cell and a bit longer. The second time the stalagmite was a needle shape about 3″ long and tapered. Both times the stalagmite leaned about 10 degrees from the vertical. The water was bottled water as bought in a Carboy for home consumption.
I have pix of both.
mehdi | November 16, 2009 at 10:44 am
I’m one of your bigest fan and almost any time you have send me an E -mail, I have been every happy and thankfull when I have read that. I am industrial hyginist and my back ground is Geology. I’ll be more than happy to talk about chemistry in these fields of science to gether .
thank you and sincerely yours.
Steve | November 24, 2009 at 8:46 am
I was just wondering if I could use Boric Acid in a fireplace in place of the Copper Sulfate. Or does the Boric Acid only work when using a menthol accelerant.
peter | November 27, 2009 at 8:44 am
hello Dr. Anne Helmenstine i was wondering if co2 desovelved in h2so3 would result in h2s04 and a carbon presipitate ? coz i’m worryed about greenhouse gasses
CO2 + 2 H2SO3 = 2 H2SO4 AND C ????
OR ARE THERE ANY PRACTICAL , GOOD WAYS TO STOP CO2 FROM COLE POWER STATIONS ?
stan baldyga | December 10, 2009 at 5:25 pm
I tried using your formula for poishing silver with disastorous results. I followed your directions.When I was finished with the project I took out the aluminum sheet containing the water with salt and baking soda and poured it down the sink. A resulting “explosion” as I can best describe reverberated into the sink area. I discovered that the plastic piping (trap) had developed a leak and dripping into the unfinished basement area. I can onlyl assume that the chemical reaction with sewer gases produced in the trap caused the explosion? I would caution anyone trying this concoction use extreme care for your safety..I am now awaiting my plumber to repair the damaged trap.
D.K. Philbin | January 13, 2010 at 5:10 am
I really enjoy your site (I am a community college chemistry instructor)! I do have a concern about your preparation of copper sulfate. In it you instruct to add the water to the concentrated sulfuric acid; it should be done in the reverse order. Adding acid to water immediately dilutes the acid and you have a larger mass of water to absorb the heat of dilution whereas when adding water to acid you only have a small amount of acid to absorb the heat of dilution and immediate boiling and other nasty things happen.
Tim | February 11, 2010 at 4:12 pm
I am a student in Chemical Engineering and I read your lab scale production of aspirin and I am looking for more information on it. I am looking specifically for reaction kinetics and equlibrium data including percent excess needed. Also, I am looking for solubility data. I would really appreciate any information that you could supply for me. Thank you very much and I hope to hear back from you.
Mujahid Hussain Shah | February 11, 2010 at 9:56 pm
Teaching is the hobby of Agles and Prophets. It is great pleasure for me learn something from you. May Almighty bless you. You live Long.
I have just joined a Desalination Plant Operator Job in UAE.
Can you guide to me a comprehensive information about the chemistry of desalination. Any book,webpage or other media. Where i can search about my required information.
Jim McDowell | February 12, 2010 at 1:58 am
Unless I am mistaken, a glass of ice water would not change it’s water level when the ice melts since the ice displaces an amount of water equal to it’s mass. Thus the water level would not change, right.
So the only ice melting that can change sea levels is the ice and snow over land masses and not ice floating in the arctic north, right?
Jose Cotos | February 12, 2010 at 7:07 pm
¿Sabe usted que aditivos hay que añadir al biodiesel en los casos que produce corrosión en el interior metálico del auto?
Guta gonfa(MSc) | February 17, 2010 at 1:29 pm
Dear Dr. Helmenstine.
I have been attending your project about com a guide to chemistry and found it intersting and peasing. Making green colored fire, objects giving light in dark, objects giving smoks ,sparks and sounds during holidays, chalk chromatogarphy are some of the poject that attract my attentions. Your work remembers methe demonstration work of one professor on a number of expriements like showing baloons of hydrogen, pop sound of hydrogen, mixture of dichromate with reactant showing soundy rxns on finger, electrochemical rxns showing colorful results , different packing of models to show crystal close packing , designed to attract or motivate students toward science and increase their imagination. I had seen this 8years ago & never forget. I am lecturer at jimma univerity Department of chemistry inorganic chemistry team leader, jimma, Ethiopia . Keep up with your beloved work ! by
Peter Ruel | March 9, 2010 at 2:16 am
Hi, Thanks for posting the alphabetical list of chemical symbols at the URL below. I spent a bit of time today making a spreadsheet for myself to double check my students’ work (my memory isn’t what it used to be) As I found this URL (at the bottom) after I’d done the work I used it to double check my info. I found a couple of my own errors but…bad news…your alphabetising skills went South in the “N’s” and the “P’s” you may want to tweak the list you posted.
Also I teach my students that the “placeholders” are NOT chemical symbols and only are the Latin way of saying the number so I don’t ask them to learn the three letter placeholders. You may want to cosider this viewpoint? Thanks again!
g.senthilnathan | March 29, 2010 at 4:49 am
i am very happy.usually read your information.i want to thank more.i am a chemistry lecturer.
Rajesh Chakravarty | March 31, 2010 at 2:40 pm
Dear Mrs. Marie,
I read your process on how to make household potassium nitrate. Could you pls advose how to seperate potassium nitrate completely from ammonium chloride in a solution. or extractign ammonium chloride from the solution made by the process described you.
Thanks & best regards.Rajesh
m. mitchell | April 5, 2010 at 6:26 pm
My 5th grader is doing the science fair project on comparing sipping through one, two and three straws. Can you give me some ideas on how to measure this and some tips on the procedure and lastly is it necessary to use different kinds of straws or length and width of straws. Your reply is greatly appreciated as his project is due in about 1 week.
uniz | April 9, 2010 at 2:04 pm
hai ma’am? im eunice from the land of far far away!! im so surprise to read facts about u!!!i hope to see u personally and ask u so many many things bout chemistry!!!but i know
javed murtaza | April 21, 2010 at 9:24 am
IN THE NAME OF ALLAH MOST GRACIOUS MOST MERCIFUL We are living in 21Century and we have got more achievmnt in Modern Science but we can not solve basic problem of human-being which is to get pure water,food and shelter.If you dont know your God who is only ONE God,Created all UNIVERSE.What is benefit you how many kind of organic or non-organic compound in the UNIVERSE..Please be serious and think about your life why ALLAH sent you here.It is a burning Question.I think to send us that we help human -beings. thank you for reading my E-mail. JAVED MURTAZA SYED MOHAMMED SAKAKA AL-JOUF KSA 00966508006023
Shawn Roberts | April 25, 2010 at 2:01 pm
What a fantasic wealth of great information. Our eight year old wants to be a scientist when he grows up and loved the smoke bomb demonstration. I may also try to incorporate some of the demonstrations into our photography business.
A quick note – Bonide Stump Remover is not KNO3 based so it was a flop but the Spectracide brand worked wonders for the smoke bomb – or the smoke disc as we are calling it. Thank you so much for your wonderful sharing!!!!
Jim Martin | April 25, 2010 at 4:02 pm
I NEED A ATTORNEY For 12 to 13 years I have taken medications for Panic Disorders. I never looked at my condition as a Panic Attack. I always looked at them as Events, a Event is when my brain skips, like someone with heart palpitation, but it my brain, a pause in my ability to think. These Events also cause a my motor skills to slip, it could be less than a second to several minutes.
My first Events started while working at Great Lakes Chemical, now known as Chemtura. At Great Lakes Chemical I was hired to do Research and Development work in plastics. I had years of experience working for Rubbermaid Inc , Reynolds Indiana. Dr. Art Blinkhorn (Dow Corning) told me there might be 10 people in the whole world that knew as much about compression molding as me. At Great Lakes Chemical, I had to learn injection molding. My job duties adding R/D flame retardants to every type of plastic made. Then preform fire tests and physical characteristics of the plastics. I first started having events while working with polyurethane foam. Foams use a chemical known as Toluene Diisocyanate ,(TDI) is an aromatic diisocyanate. It is produced for reaction with polyols to form polyurethanes. TDI is a very toxic chemical as is and was handled with extreme care. I was taken to the emergency room, due to a exposure once. But my events, I assumed were low levels of TDI exposure daily.
The first 6 months to a year after my emergency room exposure, I saw every type of doctor known to man. There was nothing wrong with me,but I was still having Events. A family doctor diagnosed me as Panic Disorders.Ive taken many different types of medication for my panic disorders. I kept reading up on panic disorders, it never made sense
.I ran in a report on PBDEs, or Polybrominated Dipheneylethers also, the other flame retardants we used Octa Deca, Penta, and other brominated flame retardants we used everyday. The report in Bloomberg discusses fact that everyone in the USA has a small amout of this chemical in there blood stream from our flame retardant leaching from electronic equipment. CERT even filed suite against Chemtura for problems that could arise in the general public from small amounts of this toxin, being in about every mammal, and in our food chain down to fish. In process of adding these toxins to plastic we literary inhaled this chemical, as a baker would flour. If a small amount of this could be a problem for the average joe walking down the road, what about me? This Events that have ruined my life can and should be traced back to PBDEs and my blood stream. The PBDEs and my short term memories loss. My motor Skill problems when a Event wont let me drive a car.
Why is it, I was never contacted? Why was I never told the health risks? Do, I end up in a nursing home because I cant remember if I took my medication, or left the stove on, whats my future? Is there anyone that cares enough to make a stand against these people, and help my situation.
Oh and believe me they knew decabrom was leaching out of electrical equipment, its in one of my notebooks there.I was told by supervisor, our Attorneys said to stop testing migration in plastics. We never new why, but shortly after that,some of us were doing age study tests on brand new TVs.
4/24/10 by Lost47960
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pradeep | May 5, 2010 at 3:28 am
I saw that you have good background physics and a little bit of chemistry. Im a Analytical chemistry M.Sc student in Srilanka and im doing a research to develop a gas sensor for detect pollutant gasses like Nox, Sox, and CO. Still we were unable to find a proper mathod for that. If you ar good in that sense im expecting your kind help for my project. Thank you.
Samantha | May 25, 2010 at 3:46 am
Hi Dr. Helmenstine,
My mother breathed in chlorine gas (chlorine vinegar) while trying to disinfect a shower full of mold. Her breathing has been affected ever since. Research says that this mixture kills virtually all bacteria and microbacteria including the healthy bacteria in the mucus membranes of the lung. Would you know of the chemical reaction that takes place when chlorine gas encounters our lungs? And if not, would you know anyone who might? Thank you for your time.
Joel | May 28, 2010 at 1:10 am
Regarding the molality example you provided at:
The first line of the example calculates moles for 10 g of NaOH. I believe the molecular weight for NaOH is off by a factor of 10. I think it should be 40 g/mol not 4 g/mol. The final answer for that line is correct at 0.25 mol.
Wayne | June 11, 2010 at 5:58 pm
Hi my wife and I have had a healthy discussion over a scientific issue, and if at all possilbe if we could get a clarification of this question.
The question is: Gravity, is it a scientific Law or Theory.
Could we get an answer to this, thank you for your time and response.
Judith Adell | June 12, 2010 at 6:22 pm
Where does one buyL uminol or BlueStar? Exactly how does one use these substances to detect blood in a stain?
Judith Adell | June 12, 2010 at 6:27 pm
Where does one go to buy the substance Luminol or BlueStar? How does one use it to detect blood stains? Please reply. Judith Adell
Larry | June 17, 2010 at 10:48 pm
take a 1/2 inch copper pipe about 18 inches long
shove a garden hose inside of it
throw it on an outside fire.
Some people drill holes in the pipe, some don’t
It is beautiful
Dr. Vrajesh | June 25, 2010 at 8:45 am
Myself Vrajesh Aghera from India, I completed my doctorate and currently I am with a chemical company. Now I want continue my study as Post doctorate, so I want some guidiance regarding it. If there is any position in your field than please inform me. I will send you my CV.
Bye and TC.
Oliver Weedon | July 2, 2010 at 4:28 am
Hi Azareal, I was trying to get my head around “How soap works” and came across your entry on About. In trying to understand it from a layman’s perspective (in order to explain it to non-chemists) I wrote this.
I’d really appreciate your input on ensuring accuracy whilst maintaining accessibility…
“Dirt gets onto our hands through oils. Dirt likes hanging out with oil so as our hands comes into contact dirt, the oil in it says, “let’s leave where we are and go onto these nice hands”, then when the oil does so, it brings “dirt” along with it. The result – dirty hands.
We decide we don’t like dirty hands and go to wash them. First we just use water, but try as we might putting dirty hands in water still leaves them dirty. Even if we rub them together in the water they will come out just as dirty as when they went in. The oils (along with their friend “dirt” likes our hands too much and don’t really like water – and that is why we need soap.
Da, da-da-da! Soap is our saviour when it comes to dealing with this problem.
A nice solid bar of soap is a very happy thing. It holds together and exists very happily all self-contained, like lots of friends sat together in a room very much enjoying each other’s company but really not wanting to leave the room. We bring that bar of soap though (with our dirty hands) into water and all hell breaks loose.
Suddenly the soap no longer stays together but bits of it start zooming out into the water. The reason for this is that one part of a “soap man” loves water and can’t resist leaving where he is and getting out into the water … to make new friends. But being a man he is a bit dipolar, one part of him loves the water friends whilst the other really hates them!
The water-hating bit of the “soap man” does his best to get away from the “water people”. To do this he gets together with other “water haters” forming a clique. This clique is like soap man MKII and has the water loving bit on the outside with lots of the water haters on the inside keeping themselves to themselves and staying as far away from the water as possible. Very powerful forces these cliques.
And back to the dirt story. Whereas oil (with it’s friend dirt) won’t mix with water (it likes the hands too much), when soap is introduced, these cliques (or micelles as Chemists call them) break up the oil (along with their dirt friends) away and off of the hands. They are serious bullies when they get together. While oil neither loves nor hates water, when soap is around it’s pushed off the hands and into the water.
This then is the clever bit, the cleaning bit. As soon as the oils (with dirt) enter the water (forced to do so by the michelles, um micelles) the micelles trap each oil (and dirt) man on the inside of their water hating clique.
You now have oil (with dirt) trapped inside a micelle (water hating clique) – and, this is the important bit, away from the hands. All that remains now is to pull the plug and wave goodbye…”
Joel | July 2, 2010 at 5:34 am
As a scientist, I find it a bit strange that you try to personify things like oil and water as if they have brains and think about who they like and don’t like.
But i do like you taking this story and running with it. This is the kind of crazyness that makes life fun. Thanks for the levity.
Oliver Weedon | July 2, 2010 at 12:46 pm
thanks for the comments Joel.
The bottom line is that I am in a position where I need to explain “how soap works” to non-scientists, people that have had very little schooling.
That means that all specialist vocab including: micelle, hydrophilic, hydrophobic, sodium, fatty acids salts etc etc. have to be “replaced” with vocab and concepts that will still allow them to access the principles involved.
I studied Chemical Physics at degree level and achieved a respectable grade although my grasp of the subject left much to be desired…. anyway that aside… whilst at University I came across several absolutely brilliant individuals that could take highly complex scientific processes and concepts and explain them in ways accessible to non-scientists.
This is what I’m aiming for with this.
My original post requested comments on the accuracy of the presentation of the concepts. I’d appreciate any input / correction you may have.
ANISH KUMAR | July 3, 2010 at 11:25 am
this is anish and i want make a chemistry project based on class 12th which ican alao perform in my school lab.
my teacher rejected my all previous ideas .she said it should be new and innovative
please help me
Jim Larsen | July 6, 2010 at 4:07 am
I have a book I would like you to consider as a science fair resource for your readers. It is “Three LTD Stirling Engines You Can Build Without a Machine Shop”. It can be seen at http://stirlingbuilder.com/. It is also available at Amazon and CreateSpace.
Frederick Frick | August 2, 2010 at 2:31 pm
Dear Doctor I am 86 years and have loved chemistry for 80 of them. I have a small lab set up and particularly love the study of qualitative analysis. The old fashion kind done with chemicals. I do not have any college degrees and never held a job in chem. But thank God for Dr. Helmenstiine’s teachings I have hundreds of pages from your Monday classes. Oh how I wish I could have been a chemist.
Jeff Gorman | August 8, 2010 at 2:58 pm
Thanks for the useful information about flame tests. I would like to do some using a blowpipe (a la James Smithson who gave the money for the Smithsonian Institution, where I am a behind the scenes volunteer), but need help getting chemicals and materials. Do you have recommended suppliers for small quantities of microcosmic salt,sodium carbonate, sodium borate and platinum wire?
Have you ever tried the blowpipe technique for flame tests and other tests of minerals? If so, do you have any guidance?
Vicky Govender | August 15, 2010 at 2:13 pm
Hi Doctor, I am designing a simple freestanding toilet made of panels that can be assembled on site. However my problem thus far is trying to convert the waste into fertilizer. Also these toilets will be used in the rural areas where there is no water. The pit tanks will be manufactured using fibreglass. I was wondering if u could assist in this regard.
Vicky Govender – South Africa
saeed | August 18, 2010 at 4:26 am
Marilyn Bloch | August 25, 2010 at 9:40 pm
Dear Dr. Helmenstein:
I want to go to nursng school but failed the TEAS test three times, although I have a B.A. in Speech and Hearing. I ran out of time on both the science and math section to finish the problem and I fail the test miserably after months of study. What can I do? I tried all of the previews on Rapid Learning.com and many review guides. I never took Chemistry in either high school or college although my father did but now he is dead. He had two years of Chemistry in high school before becoming a court steno. He had too many problems with Algebra to pursue his love, radio engineer which he loved but failed Algebra. I tried to learn the atoms and Chemical formulas for the test but it did not do any good all of my studies. I cannot find a nursing school that does not have this miserable entrance test. If I went for another BSN at some colleges, they only want me to take the pre-requisites but do not require the nurse entrance test. It is really awful. I do not think I could ever pass it, and it is the same test over and over. The proctor said I should not leave any blank answers but the test does not give you time to finish so I guessed wrong.
tiur lum phd | August 30, 2010 at 9:26 am
Hi mrs Helmenstine
i really glad to read about your blog and your honestly about science. As you know i try to be PHD student from 2004 till now (you can’t imagine how bad ppl and circumtances around my dreams) so very difficult to go. I also learnt that not only because they were clever they get certificate or PHD, but also because they have a lot of money to buy and to pay the bill.
I face so many conflict but honestly i never hates science or biotechnology as my majoring subject. Chemistry i Got A in my bachelor because i like it. Nice to meet you,i hope to see you here, teaching with honestly heart…take care
sandra ekstrom | October 6, 2010 at 7:30 pm
I cannot get my jellow to glow and I used 2 cups of quinine in the recipe. My black light is 75 watt 120v standard base. I promised my students that we would make this during the month of October. Please help me.
azareal | October 6, 2010 at 7:33 pm
It’s your black light. The screw-in kind aren’t really black lights (are not ultraviolet light), but just mask most of the incandescent spectrum. You need a black light, like the kind based on a flluorescent bulb.
Lorenzo Guel-Camp | October 7, 2010 at 1:53 am
I am a middle school student and want to do a science fair project with chalk chromatography, but everything about chromatography is either written at a very hard reading level or,, in the chalk chromatography experiment I found on line, does not very clearly meet the science fair standard of naming the control and variables, quantifying and explaining results. Can you help me to think about and design this experiment more scientifically? PS I like your smoke bomb video!
wes | October 10, 2010 at 1:39 am
Following a hot fire that leaves an entire house coated in soot and smoke (such that the house will be gutted), do you suppose that dishes and cookware which have been exposed to the soot and smoke are safe to use after washing?
Stephen Sher | October 25, 2010 at 4:19 am
I am a high school student in an international school in Beijing. I am doing an extended report on nitrocellulose.
I read your post on about.com on how to make nitrocellulose (flash paper) and found it very useful.
I would help me greatly if I am able to contact you directly through email to ask a few questions on the making of nitrocellulose and the combustion of nitrocellulose.
Please let me know if this is possible. Than you
Mark | November 22, 2010 at 1:56 pm
Hello, I am wondering about the Briggs Rauscher reaction you have posted. My son is doing a science fair project on this and he ordered a BR kit from teachersource.com. The kit has him go through the steps meticulously, which he did, but his first BR reaction took over 24 hours to finish, when 1/2 hour between reactions. What controls the clock rate and how can this reaction be ‘sped up’? He used hand stirring, and liquids at room temperature. Would this affect the BR rate in such a negative way?
thanks in advance for any help or suggestions you can offer.
Tomeka | December 7, 2010 at 3:52 am
I just read ” What materials glow under black or ultraviolet light?
Can you explain why the brown of someone’s eyes would glow under such lighting?
She’s a healthy women in her 30’s with the exception of she has G6PD. And with that the doctors told her not to over due vitamin C, no blood thinners, and no anti-malaria injections…..
jimmy Dsouza | December 12, 2010 at 8:31 am
you really explain well but the thing is that i am little weak in mole concept so if u can help me with basics with understandings i will be really obliged:)))i am from india
Shawn Green | March 8, 2012 at 4:00 pm
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