Chemistry

Is the walnut black pigment in unripe green walnuts due to melanin??

I have tested for the decrease in the amount of starch in a sample of rice left at room temp for days. I have seen significant decrase due to the decreasing intensity of iodine blue black color. Howeever, unlike the initial fesh rice the test on subsequent degraded samples shows a color say light purple which gradually fades away in 2-3 min and becomes colorless..my basic question is why in degrading starch does the color intensity of iodine test gradually change from slight blue black to no blue black??

We are in an area that has hard water.... however, it also seems quite aerated when it comes out of our tap. The pH when delivered from the tap is ~ 7.2 to 7.4. (higher than 7, presumably due to the hardness and chalkiness of the water). When left in a beaker or a closed container overnight the pH increases to 8.4 - 8.6. (this can be accelerated to a few by mins boiling it in a kettle) We have a theory as to why this is, but does anyone know for sure what is happening? If so then please explain. Our speculative reasoning: - the hardness of the water is causing it to be pH 8.6 instead of 7. Dissolved gasses and C02 in the water straight from the pipe c…

Using baking soda and vinegar, distilling what is left, putting that in a filter, then redistilling it, then filter it with lifestraw or something?

I heated a piece of banana peel in conc. Hcl and gradually the solution developed a blood red color !!!! Any speculations over what may have caused this ???

I'd like to find some base course about general chemistry. At first I've seen some lectures in Khan academy, but I think they're very low quality and short. Where can I find hi-quality online lectures? I'd like one standard course, long (1-2 term) and detailed. What do you think about MIT courses?

i have some small ABS plastic parts and i wish to "yellow" them a bit, the kind of yellowing that you often see from sun damage or just over a long time like how old gray computer keyboards often discolor over many years. I would like to construct some kind of small box or device that i can put outside in the direct sunlight, and put the small parts inside this device, and have it intensify the UV light / rays / exposure to the small parts so that it speeds up whatever the yellowing process is. So my question is, how can i accomplish this? How can i magnify or intensify the light without totally melting or destroying the parts? I should also note that i want the expos…

So I have been looking into heat dissipation and aside from silver, I have narrowed it down to aluminum and copper heat tape. I have heard that copper heat tape is preferred for heat dissipation but it has a lower specific heat than aluminum. My initial theory was that the higher the specific heat, the faster rate of dissipation. Am I missing something? Should I continue with using copper tape for heat dissipation. Any to all advice is greatly appreciated, thank you!

I know negative order wrt a reactant signifies an inverse effect on the rate... However can i know an example of such a situation? Moreover products cannot be included in the rate bcos they dont affect the rate so wat bt this reaction: 2O3--> 3O2 rate= k[O3]^2 [O2]^-1 Firstly, on what grounds is this product O2 included in rate law eq. Secondly , the rate is actually undefined instead of 2-1=1 Plz explain...

Does any body know from where all that salt came into the sea and oceans ? lake or river water do not contain any salt so from where

Why mass number denominates "A" and atomic number - "Z" ? I couldn't find it anywhere. Maybe "A" derivated from some Latin word starts which "A"?

I've read that accountant in business is fundamental. what do you think about this? Can you make good money using chemistry in business?

Hello, Recently I came across the conversion of 1,10 Phen to Phen dione, using KBr HNO3 and H2SO4. I am not able to find a mechanism for the conversion. I will be grateful, if anyone will help me with that.

Is mild white turbidity a positive result for iodoform test in a sample suspected to contain ethanol?? Also shouldnt glucose n other sugars also show positive for test for alcoholic group....what bt iodoform test with glucose ?

Will prussian blue i.e. ferric ferrocyanide be decolorized by hcl ?

What is the best thing to do when your clothes get wet after it rains and the clothes had been washed prior and left to dry in the clothes line outside?

I was demonstrating the electrolysis of salt-water to some of my friends and family, and decided to leave it going to collect some of the gas in tubes in the water. When I returned (about 1.5 hours later) there was a brown, fluffy precipitate and the water had turned a yellowish colour. Anyone have an idea of what this is or a link to a thread with the answer? Thanks!

Today my newspaper (UK) reproduced some sample GCSE questions. And they left me baffled - I certainly would have failed such a test. One chemistry question asked: Complete the word equation for the oxidation of hydrogen. hydrogen + oxygen =? The answer is water. So where did the second hydrogen atom come from?? It doesn't say hydrogen2, it just says hydrogen! And what's more if two hydrogen are somehow to be assumed, why not assume two oxygen - or any other numerical combination? Surely, if it means two it should say or indicate two. There is another whereby numbers seem a tad loose. Anyway, the upshot is I'd fail a GCSE test with flying colours.

I understand fire as just being highly energized gas molecules. Therefore, blue flame is hotter than a red flame, because the gas molecules are much more excited, right? ~ee

I was just burnt myself after making some food in the oven. The towel (fabric) insulated my hands for a short time, but the heat shot up rapidly after before I could react. My question is, would I have been better off wetting the towel first? Intuition tells me the wet towel will heat up more gradually (better thermal capacitance?) giving me more time to react, but the wet towel should be worse at steady state, since I think water has a better thermal conductivity than the dry fabric. Normal usage is probably shorter than the time taken to reach stead state, so i assume this is not a factor. Thoughts?

Hi dear friends I work with sulfuric acid and 0.75HNO3+0.25HCL for a gold refining project. The main problem is the huge amount of those acid vapors in the place. Did any body have the same problem? Could we get and filtrate the acid vapor with the activated carbon? Any related help is really appreciated. Thanks all

Dear friends I've synthesized alumina foams with nice open porosities and also good mechanical strength. As you know the specific surface area of such material is very low (~2 m2/g). My question from you, chemists, is that how I can improve the specific surface area of this material to high values such as 800m2/g to use it as absorbers. ? Any useful help is really appreciated. Thanks all

Hi. I have this project that im working on with natural resin. The resin i'm using is Elemi gum. The resin has a strong lemon smell. And i wanna do essential oïl with it. But my question is. What is gonna be my resin after? Is it still gonna be a resin and does the resin will still have his strong lemon smell or does the smell disapear with the distillation? Thank You

I need help in my assignment to balance a chemical equation. Help me to solve it. This is the equation. Hg(OH)2 + H3Po4 = Hg3(Po4)2 + HOH How to balance it?

Are there any commercial products rich in phosphate like in medicines or some food or any other thing