Number of moles of $K_2Cr_2O_7$ reduced by one mole of $Sn^{2+}$ ions is

Permanganate $(VII)$ ion,$MnO_4^-$,in basic solution oxidises iodide ion,$I^-$,to produce molecular iodine $(I_2)$ and manganese $(IV)$ oxide $(MnO_2)$. Write a balanced ionic equation to represent this redox reaction.

What is the oxidation state of chromium in the final product formed by the reaction between $KI$ and acidic $K_2Cr_2O_7$ solution?

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?

Consider the following reaction occurring in basic medium $2MnO_4^- (aq) + Br^- (aq) \to 2MnO_2 (s) + BrO_3^- (aq)$. How can the above reaction be balanced further?

The number of moles of oxalate ions $(C_2O_4^{2-})$ oxidized by one mole of permanganate ions $(MnO_4^-)$ in acidic medium is