Redox Reactions in Terms of Electron Transfer — Prelims Questions

In the reaction: $\text{MnO}_2 + 4\text{HCl} \rightarrow \text{MnCl}_2 + \text{Cl}_2 + 2\text{H}_2\text{O}$, which species is acting as the oxidizing agent?

Which of the following statements correctly describes the process of oxidation in terms of electron transfer?

In the reaction $\text{Fe}^{2+} + \text{Ce}^{4+} \rightarrow \text{Fe}^{3+} + \text{Ce}^{3+}$, identify the reducing agent.

Consider the reaction: $\text{Zn(s)} + \text{CuSO}_4(\text{aq}) \rightarrow \text{ZnSO}_4(\text{aq}) + \text{Cu(s)}$. Which of the following represents the reduction half-reaction?

Which of the following reactions is NOT a redox reaction?

In the disproportionation reaction of hydrogen peroxide: $2\text{H}_2\text{O}_2(\text{aq}) \rightarrow 2\text{H}_2\text{O}(\text{l}) + \text{O}_2(\text{g})$, what is the change in oxidation state of oxygen?