The reaction of $Na_2S_2O_3$ with iodine gives

Acidified potassium permanganate solution is decolourised by

Which of the following can act both as an oxidizing and a reducing agent?

$2KMnO_4 + 3H_2SO_4 + 5H_2O_2 \rightarrow K_2SO_4 + 2MnSO_4 + 8H_2O + 5O_2$. Find the normality of $H_2O_2$ solution,if $20 \ mL$ of it is required to react completely with $16 \ mL$ of $0.02 \ M \ KMnO_4$ solution. (Molar mass of $KMnO_4 = 158 \ g \ mol^{-1}$)

Which of the following reactions does not involve either oxidation or reduction?
$I. \ 2Cs + 2H_2O \to 2CsOH + H_2$
$II. \ 2CuI_2 \to 2CuI + I_2$
$III. \ NH_4Br + KOH \to KBr + NH_3 + H_2O$
$IV. \ 4KCN + Fe(CN)_2 \to K_4[Fe(CN)_6]$

Which of the following are non-metal displacement reactions?
$(A)$ $Ca_{(s)} + 2 H_2 O_{(l)} \longrightarrow Ca(OH)_{2(aq)} + H_{2(g)}$
$(B)$ $V_2 O_{5(s)} + 5 Ca_{(s)} \stackrel{\Delta}{\longrightarrow} 2 V_{(s)} + 5 CaO_{(s)}$
$(C)$ $2 Fe_{(s)} + 3 H_2 O_{(g)} \stackrel{\Delta}{\longrightarrow} Fe_2 O_{3(s)} + 3 H_{2(g)}$
$(D)$ $Cr_2 O_{3(s)} + 2 Al_{(s)} \stackrel{\Delta}{\longrightarrow} Al_2 O_{3(s)} + 2 Cr_{(s)}$