Concept of Oxidation and Reduction — Prelims Questions

Which of the following statements is INCORRECT regarding oxidation and reduction?

In the reaction $2H_2S(g) + SO_2(g) \rightarrow 3S(s) + 2H_2O(l)$, identify the oxidizing agent and the reducing agent.

Which of the following reactions represents a disproportionation reaction?

What is the oxidation number of chromium in $K_2Cr_2O_7$?

In the reaction $MnO_4^- + 5Fe^{2+} + 8H^+ \rightarrow Mn^{2+} + 5Fe^{3+} + 4H_2O$, which species is the oxidizing agent?

Which of the following elements always exhibits a +1 oxidation state in its compounds?