Question

When solid S1 is heated, it breaks up into gas G and another solid S2. The solids S1 and S2 and the gas G are all pure substances. On the basis of this information alone, which substance or substances must be compounds? A.S1 only B.S2 only C.S1 and S2 D.S1 and G

Answer 1

Answer:

A.S1 only

Explanation:

A compound is one of the pure substances (other being element) that forms when two or more atoms of an element are chemically combined. According to this question, a solid S1 is heated and it breaks up into gas G and another solid S2 as follows:

S1 (s) ➡ G (g) + S2 (s)

Based on the information in the questio, the solids S1, S2 and the gas G are all pure substances. However, since solid S1 broke down into two other pure substances, it means solid S1 is originally a chemical combination of both products, which denotes a COMPOUND. Note that Gas G and Solid S2 are most likely elements.