When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.

33 What do you mean by a precipitation reaction? Explain giving an example. 34 Explain the following in terms of gain or loss of oxygen with one example each:

(i) oxidation (ii) reduction

35 Define the following in terms of gain or loss of hydrogen with one example each:

(i) oxidation (ii) reduction

35 When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.