For the balanced equation $NO_3^- + 4H^+ + ne^- \to 2H_2O + NO$,the value of $n$ is ........

What will be the coefficients $x, y, z$ in the balanced form of the following redox equation: $xIO_3^- + yHSO_3^- \to zI^{-} + pH^{+} + qSO_4^{2-}$?

$KMnO_4 + HCl \rightarrow MnCl_2 + Cl_2 + KCl + H_2O$. In the above reaction,how many moles of $H_2O$ would be formed for each mole of $Cl_2$ liberated?

Which of the following is a redox reaction?

The number of electrons required to reduce chromium completely in $Cr_2O_7^{2-}$ to $Cr^{3+}$ in acidic medium is:

Manganese ions $(Mn^{2+})$ can be oxidised by persulphate ions $(S_2O_8^{2-})$ according to the following half-equations:
$S_2O_8^{2-} + 2e^- \longrightarrow 2SO_4^{2-}$
$Mn^{2+} + 4H_2O \longrightarrow MnO_4^- + 8H^+ + 5e^-$
How many moles of $S_2O_8^{2-}$ are required to oxidise $1 \ mole$ of $Mn^{2+}$?