Chemistry - Mole Concept Question with Solution | TestHub

Explain the Question : Identify the correct classification for a pure substance.

Concept : This question is based on classification of matter.

Solution : Matter is broadly classified into pure substances and mixtures. Mixture, like hetterogeneous mixture (option 4), consist of two or more substances physically combined and are not pure. Pure substances have a fixed chemical composition and uniform properties. Pure substances themselves are divided into two categories : elements (like ${\mathrm{O}}_2,\mathrm{Fe}$ ), which are made of only one type of atom and cannot be broken down by chemical means, and compounds (like ${\mathrm{H}}_2\mathrm{O},{\mathrm{CO}}_2$ ), which are made of two or more element chemically bonded in a fixed ratio. Therefore, a pure substances can be either an element (option 2 ) or a compound (option 1). Option 3 correctly includes both possibilities.

Final Answer : C