Question

Sample 'A' is mixture of iron fillings and sulphur powder. Sample 'B' is a compound of iron sulphide. A31eema was asked to study the effect of hest on both sample 'A' and 'B'. Which of the following observations was incorrect?
(a) Yellow colored sulphur from sample 'A' starts melting.
(b) Sample 'A' mixture of iron and sulphur glows
(c) No effect of heat on sample 'B'
(d) Colour of sample 'B' changes from black to yellow

CBSE Class IX Science VSA (1 Mark)

Answer 1

Answer:

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Answer 2

Answer:

(b) Sample 'A' mixture of iron and sulphur glows

Explanation:

When a mixture( A) of iron fillings and sulphur is heated, a compound FeS - iron sulphide is formed.

Fe + S → FeS

When dilute HCl is added the reaction becomes -

Fe (s) + S (s) + 2 HCl (aq) → FeCl2 + H2

Sulphur remains unreacted H2S gas that has a foul smell which makes the solution black when it passes through the lead acetate solution. With a pop sound, hydrogen gas burns.