Give reasons for the following:
(i) Metals conduct electricity.
(ii) Reaction of nitric acid with metals generally does not evolve hydrogen gas.
(iii) For making gold ornaments, 22-carat gold is preferred to 24-carat gold.
(i) Reasons: Metals have free electrons which helps in the flowing of electricity through it.
(ii) Nitric acid is a strong oxidizing agent. So, as soon as hydrogen gas is formed in the reaction between a metal nitric acid, the nitric acid oxidizes hydrogen gas to water and itself gets reduced to any of nitrogen oxides.
(iii) 24 carat gold i.e., pure gold is very soft that’s why pure gold is mixed with copper to make it hard. Which is 22-carat gold and make it suitable for jewellery.