Question
How does dihydrogen react with:
(a) non-metals (b) metals and (c) metal oxides?
Solution
(a)Reaction of dihydrogen with non-metals:
(i) With halogens: Dihydrogen forms hydrogen halides with halogens. With fluorine, the reaction is very violent and the reactivity decreases in the order Cl2, Br2 and I2.
(ii) When nitrogen: When a mixture of dihydrogen and dinitrogen under pressure is passed over finely divided iron containing traces of molybdenum at 673K, it produces ammonia.
(iii) With oxygen: Dihydrogen combines with oxygen either at 970 K or by passing electric spark into the gaseous mixture to form water vapours.
(i) With halogens: Dihydrogen forms hydrogen halides with halogens. With fluorine, the reaction is very violent and the reactivity decreases in the order Cl2, Br2 and I2.
(ii) When nitrogen: When a mixture of dihydrogen and dinitrogen under pressure is passed over finely divided iron containing traces of molybdenum at 673K, it produces ammonia.
(iii) With oxygen: Dihydrogen combines with oxygen either at 970 K or by passing electric spark into the gaseous mixture to form water vapours.
(iv) With sulphur: When dihydrogen is bubbled through molten sulphur at 700 K, hydrogen sulphide is produced.
(v) With carbon: Dihydrogen combines with carbon to form methane or acetylene depending upon the condition of the reaction.
(b) The combination with metals (Dihydrogen acts as an oxidising agent): Dihydrogen combines with metals like sodium, potassium and calcium upon heating to from corresponding hydrides.
These hydrides are of ionic nature (salt-like). In the above reactions, hydrogen acts as an oxidising agent.
(c) Combination with metallic oxides(Dihydrogen acts as a reducing agent):
Dihydrogen reduces heated metal oxides to metals.
(v) With carbon: Dihydrogen combines with carbon to form methane or acetylene depending upon the condition of the reaction.
(b) The combination with metals (Dihydrogen acts as an oxidising agent): Dihydrogen combines with metals like sodium, potassium and calcium upon heating to from corresponding hydrides.
These hydrides are of ionic nature (salt-like). In the above reactions, hydrogen acts as an oxidising agent.
(c) Combination with metallic oxides(Dihydrogen acts as a reducing agent):
Dihydrogen reduces heated metal oxides to metals.
