Redox Reactions(12th Grade > Chemistry ) Questions and Answers
Explanation:-
Answer: Option B. -> Reducing action of H2S:
B
In this reactionH2O2 acts as an oxidising agent and H2S acts as a reducing agent as sulphur gains electron and changes its oxidation state from -2 to 0. As its oxidation state increases, it reduces other reactants.
Explanation:-
Answer: Option C. -> MnO−4/Mn2+, E0=+1.52:
C
Reduction potential is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced. Measured in volts (V), or millivolts (mV) - each species has its own intrinsic reduction potential. The more positive the potential, the greater the species' affinity for electrons and tendency to be reduced. Hence - among the given options - MnO−4is strongest oxidising agent. In other words -MnO−4 has the best affinity to get reduced and thus has the greatest ability to oxidise.
Explanation:-
Answer: Option A. -> an oxidising agent:
A
First - let us write down the reaction:
SO2+2H2S⟶3S+2H2O
In H2S, sulphur has an oxidation number of-2. In SO2 Sulphur has an oxidation number of +4.
On the right-hand side, we only have elemental sulphur whoseoxidation number is 0. The sulphur in SO2 changes its oxidation number from +4 to 0.
This means that the sulphur is gaining electrons. We know that when a reactantgains electrons,it gets reduced. Hence, SO2 is getting reduced.
Also, the reactant that gets reduced is the oxidising agent. Hence, here, SO2 acts as an oxidising agent.