Tagged Questions

Questions asking for identification of compounds on photos, or given by formula.

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3
votes
2answers
71 views

How to get back my beautiful crystals made from iron and sulphuric acid

I have put some old nails and screws in the 30% sulfuric acid to prepare an electrolyte for plating. After some bubbling and horribly irritating smell (probably $\ce{SO2}$), the reaction slowed down. ...
6
votes
3answers
1k views

Which chemical is responsible for making marker ink permanent?

As asked in the question and also, a bonus question: which property of a chemical would make it 'permanent' in terms of markers?
5
votes
1answer
123 views

Scary jelly forming on zinc anodes

I'm continuing with my electrolysis experiments. Over a long time, I seek a perfect electrodes. It seems, that when you pick the right anode and cathode, it might be a lot cheaper than universal ...
6
votes
1answer
316 views

Does knowing the ratio of masses of the elements in a compound lead to the unique chemical identity of the compound?

I was posed this question from a friend, however I am not necessarily sure. I think: yes, because a molecule of any compound is composed of a whole-number ratio of atoms of its elements, per the law ...
7
votes
1answer
705 views

What is C2H5-O-CH=CH2?

Someone painted an original graffiti: source I wonder what kind of reaction was depicted; what's that product substance? The graffiti reads: $\ce{C2H2 + C2H5OH -> C_2 H_5 - O - CH = CH_2}$ ...
2
votes
1answer
322 views

Why is oxygen absorbed in a colorless alkaline solution of pyrogallol and why does it turn dark brown?

I'm reading about recognition and identification of gases. My book says: Oxygen is absorbed in colorless alkaline solution of pyrogallol and turns dark brown? I'd like to know why and how. ...
0
votes
1answer
45 views

What copper oxide is being created upon electrolysis?

Whenever using copper as anode, I end up with cyan dust that doesn't dissolve in water. What's that (presumably) oxide? Is it poisonous? Can I dissolve it in something to perform electroplating ...
0
votes
1answer
48 views

Naming an ensemble of compounds

As part of intern work I am running simulations on a group of compounds, but as it is I have little in the way of O-Chem experience and I wanted to be able to at least get some direction on naming ...
2
votes
1answer
113 views

Identifying 5 unknown substances

Please help me identify the following 5 substances; G, Y, T, L and J G is a white solid which is insoluble in water. Consider the following reactions carried out on solid G. Step 1: Excess dilute ...
3
votes
3answers
90 views

How to read a given chemical formula?

I'm trying to read this chemical formula but I'm a bit confused. I'm hoping that someone could help break this down for me to explain what the various parts mean. Someone purchased epigallocatechin in ...
2
votes
2answers
159 views

How to identify ionic compounds

I have a Chemistry lab in which I must design and carry out an experiment to determine the compound in each of eight numbered vials. Each vial contains one of these ionic compounds: BaCl2 CaCO3 ...
2
votes
1answer
262 views

What substance is used for staining brass?

While working at CNC engraving, I had at my disposal a small bottle of liquid used to stain brass for creating signs etc - engrave a writing, stain the engraving, then grind/polish the flat topmost ...
3
votes
3answers
463 views

How do we actually know the chemical structure of a compound?

If a compound is placed before you and you are asked to determine what it is and what it's structure is,how do you actually do that ? This might be a baby question for most of you but I am not from ...
3
votes
1answer
108 views

What is the best way to detect the presence of tear gas?

I realise that tear gas can be several different things (Pepper spray / CS Gas / CR gas, PAVA, etc) Is there a good way to detect some or any of these in the air? Ideally using an electronic sensor ...
3
votes
2answers
840 views

Electrolysis of molten Calcium Chloride: Identifying the product

I was trying to make Calcium metal by electrolyzing molten $CaCl_2$. I used a stainless steel spoon and a thick steel wire as electrodes. Then I attached them to a power supply. I placed some $CaCl_2$ ...
3
votes
3answers
900 views

Presumptive test for modafinil?

Given a sample that is probably modafinil plus common fillers, but could be fake, what reagent tests would best determine whether it contains modafinil? Assume a known-good sample for comparison. ...
1
vote
0answers
72 views

DNA qualitative analysis [closed]

Does DNA give positive tests for: Amides (using Hinsberg , isocarbonyl or any such test) Alcohols Phosphates (using the Ammonium Molybdate test)? I will be extracting DNA from fruits and ...
6
votes
1answer
562 views

Identifying a glass frosting chemical

I have purchased an "unknown" white coloured powder from the market which can frost glass objects. Here are some properties of this powder White in colour When mixed with HCL or water, it results in ...