When is something *not* a chemical?

Factual Questions
1

I’m trying to wrap my head around some basic chemistry concepts, but I am struggling to get a clear definition of chemical. I know some examples of what are definitely chemicals:

Gold
Water
Salt

… etc, but what about substances that are made up of more than one type of molecule? Eg, salt water, which contains H[sub]2[/sub]O molecules as well as NaCl molecules.

Is salt water a chemical?

When is something not a chemical?

2

The noun “chemical” doesn’t really have a precise agreed-upon definition. That’s why chemistry uses more specific terms like element, compound, solution, suspension, etc.

3

Never. Everything, including you are made from chemicals.

4

I don’t know if salt water is a chemical. It is a solution. A chemical implies it is a single compound doesn’t it?

5

Generally anything that is one particular molecule is a chemical. So, wood is not a chemical, as it is made up of many different types of molecules. Salt water is a solution, with one chemical dissolved in another, so you wouldn’t call salt water a chemical either.

Generally.

You might call mineral oil a chemical, yet mineral oil is a mixture of hydrocarbon chains of varying lengths and often with impurities – so, a bunch of different molecules. But since the impurities are at a low level and since a 22-carbon chain acts pretty much just like a 23-carbon chain, one sort of doesn’t care in most applications that it is really made up of different molecules.

Anything much more strict than this isn’t necessary, as it is usually pretty clear what’s going on. If something more strict is necessary, words like those friedo listed are used.

6

Salt water is not a mixture of salt and water, but an aqueous solution of sodium, potassium, calcium, chloride, iodide, etc., ions (plus impurities). So it would constitute a “chemical” as opposed to a mixture of distinct chemical compounds.

7

How can you define a single compound? Compound, by definition consists of two or more other things, well, compounded.

8

I would amend my answer with:

Actually, many solutions would be called chemicals, for instance hydrochloric acid.

A little Jacobellis v. Ohio (1964), anyone?.

9

There are ions in the solution, but they are not a discrete group that is named ions. What the heck do you think “ions” are. And for extra thought, the “impurities” in pure water are the salt, potassium, calcium. iodide, etc.

10

I think that what you’re referring to is not salt water, but perhaps sea water. Surely you’ll agree that if I dissolve pure salt into pure water, that would indeed be “salt water”, wouldn’t it?

11

ETA, the reference above to pure water was meant to be sea water, municipal water, or any water that we are likely to encounter. In other words, I there is no “pure water” we encounter.

12

The notion that, for example, “I don’t want to eat food with chemicals in it” is silly.

I suppose you could say that neutronium is not a chemical (what neutron stars are made of, though I don’t think we understand much about its properties), but that doesn’t convey any useful information.

13

Thanks for the answers.