Question

Which of the following are not compounds?
A.Potassium chloride
B.Carbon monoxide
C.Iron sulfide
D.Sulphur powder

Answer 1

Hint: Compound is a combination of two or more elements in a specific ratio or in relative proportions. A chemical formula is basically an expression that represents the elements in that compound along with its relative proportion in the compound.

Complete answer:
- A compound is a substance created by when two or more chemical elements are bound together. There are so many examples of compounds that are used on a regular basis such as sodium chloride, hydrochloric acid, etc.
- The types of bonds holding together in a compound can vary i.e., ionic bond or covalent bond.
- The elements are present in a fixed ratio whether it is available in any compound.
- Potassium chloride is a metal halide salt, thus a compound since it is made up of potassium and chlorine.
- Carbon monoxide is a gaseous mixture composed of carbon and oxygen. Thus, it is also a compound.
- Iron sulfide is made up of sulfur and iron. It is also a chemical compound.
- Sulphur powder is not a compound since sulfur is an element which is found in powder form.

Note:
Both compounds and elements come in the category of pure substances. Elements contain only a kind of atom which cannot be broken down into any simpler matter by either chemical or physical methods.