Consider a titration of potassium dichromate solution with acidified Mohr's salt solution using diphenylamine as indicator. The number of moles of Mohr's salt required per mole of dichromate is

In acidic medium,iodide $(I^{-})$ is oxidized to iodine $(I_2)$ by $KMnO_4$. What is the change in the oxidation number of manganese in this reaction?

Which of the following is a redox reaction?

The equivalent weight of ${S_2O_3^{2-}}$ in the reaction where it acts as a reductant is ...... . ${2S_2O_3^{2-} + I_2 \rightarrow S_4O_6^{2-} + 2I^-}$

Consider the following equations:
$2 Fe^{2+} + H_2O_2 \rightarrow x A + y B$
(in basic medium)
$2 MnO_4^{-} + 6 H^{+} + 5 H_2O_2 \rightarrow x' C + y' D + z' E$
(in acidic medium)
The sum of the stoichiometric coefficients $x, y, x', y'$ and $z'$ for products $A, B, C, D$ and $E,$ respectively,is............

Consider the following statements:
In the chemical reaction:
$MnO_2 + 4HCl \to MnCl_2 + 2H_2O + Cl_2$
$(1)$ Manganese ion is oxidised
$(2)$ Manganese ion is reduced
$(3)$ Chloride ion is oxidised
$(4)$ Chloride ion is reduced.
Which of these statements are correct?