Name: Uses of Hydrogen
Uploaded: 2019-07-19
Duration: 3 min 14 s
Description: We know about the physical and chemical properties of hydrogen and its production process. Let's learn about its uses in welding, production of ammonia, and...

Question

A black metallic oxide 'A' on reaction with colourless and odourless gas 'B' forms pinkish red metal 'C' and colourless liquid 'D'.

(i) Identify A, B, C and D.

(ii) Give a balanced chemical equation for the reaction.

(iii) What is the purpose of gas 'B'?

(iv) Give two tests for colourless liquid 'D'.

Accepted Answer

(i) A black metallic oxide A is Copper oxide ( $CuO$ ).

The colourless and odourless gas B is Hydrogen gas ( $H_{2}$ ).

The pinkish red metal C is Copper ( $Cu$ ).

The colourless liquid D is water ( $H_{2} O$ ).

(ii) The equation must be balanced in order to follow law of conservation of mass. The balanced chemical equation is $CuO + H_{2} \to Cu + H_{2} O$ .

(iii) Hydrogen(B) acts as a reducing agent here. Hydrogen is used for the reduction of metals, production of hydrochloric acid, hydrogenation of fats and oils.

(iv) Pure copper sulphate is white and is anhydrous in nature. When water is added, copper sulphate turns blue.

Cobalt (II) chloride is blue and is anhydrous in nature. When water is added, cobalt(II) chloride turns pink.

Important Questions on Study of First Element - Hydrogen

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