Question

Which of the following statements are true for pure substances?

(i) They have constant properties throughout.
(ii) They can be compounds or mixtures.
(iii) They have the same composition throughout.

• A. Both (i) and (ii)
• B. Both (i) and (iii)
• C. Only (i)
• D. All (i), (ii) and (iii)

Answer 1

The correct option is B Both (i) and (iii)

• Pure substances are the substances that have constant composition and constant properties throughout.
• They can be classified as elements and compounds.
• Mixtures are formed by the physical combination of two or more substances. They are not the pure substances.

Therefore statements (i) and (iii) are true for pure substances.