Question

Identify the substance oxidised and reduced in each of the following reactions:

i) 3MnO2 + 4Al → 3Mn + 2Al2O3

ii) CuO + H2 → Cu + H2O

iii) 2H2S + O2 → 2H2O + 2S​

Answer 1

Answer:

3MnO2 + 4Al ---> 3Mn + 2Al2O3. Mn is reduced. ... OXIDISING AGENT IS OPPOSITE OF OXIDATION AND REDUCING AGENT IS OPPOSITE OF REDUCTION. SO, Mn is a oxidising agent

This is an oxidation-reduction reaction, in which some species are oxidized and some reduced. The oxidation number of copper goes from +2 (in CuO) to 0 (in Cu), while hydrogen's oxidation number goes from 0 (in H2) to +1 (in water). The oxidation number of oxygen stays the same and is equal to -2.

Of S is increasing from - 2 to 0 so sulphur is undergoing oxidation while in O2 - > H2O Oxidation no. Of oxygen is decreasing from - 2 to zero.. So it is undergoing reduction.. Every reaction becomes easy in context of finding oxidised and reduced species..

Explanation:

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