Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved. (a) What type of substance is B? (b) What type of substance is C? (c) Name the gas (i) D, and (ii) E? (d) Write one characteristic property of gas D.

Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved.
(a) What type of substance is B?

(b) What type of substance is C?

(c) Name the gas (i) D, and (ii) E?

(d) Write one characteristic property of gas D.

(a) Substance B is a mixture (Fe + S).

(b) Substance C is Compound (Iron sulphide, FeS).

(c) (i) Hydrogen sulphide, H₂S

(ii) Hydrogen, H₂

(d) Hydrogen sulphide has smell of rotten eggs.

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