Question

identify the substance that are oxidised and the substance which are reduced in the following reaction​

Answer 1

Answer:

Hi

Explanation:

(i)The substance oxidised is sodium and the substance reduced is oxygen gas.

(ii) The substance oxidised is Hydrogen gas and the substance reduced is copper oxide.

Answer 2

Answer:sodium

Explanation:

Sodium atom to sodium ion: oxidation, e loss, ox. state change is from 0 to +1 .2 x Na increases, each from (0) to (+1), losing one electron per Na atom, which is 'electronically' balanced by the oxygen molecule to peroxide ion: reduction, e gain, ox. state change 2 x O decreases, each from (0) to (1), gaining two electrons per O atom (or two electrons per O  2 molecule), and the halfreactions are:

(i) oxidation: Na →  Na  +   + $$e^$$ (formation of sodium ion)

(ii) reduction: O  2  + $$2e^$$ →  O  2

​  −−   (formation of the peroxide ion)

Adding and balancing 2 x (i) + (ii) gives the full equation

4Na (s) + O  2  (g) → 2Na  2  O(s)

Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced