In the following reaction sequence,the $\%$ yield for reaction $I$ is $60 \%$ and that of reaction $II$ is $50 \%$. The overall yield of the complete reaction is $..........\%$ [nearest integer].

$A$ mixture of $CaCl_2$ and $NaCl$ weighing $4.44 \ g$ is treated with sodium carbonate solution to precipitate all the calcium ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get $0.56 \ g$ of $CaO$. The percentage of $NaCl$ in the mixture is (atomic mass of $Ca=40$)

What is the volume of $0.1 \, N \, HCl$ required to react completely with $1.0 \, g$ of pure calcium carbonate? (in $cm^3$)

The density of $2 \ M$ aqueous solution of $NaOH$ is $1.28 \ g \ cm^{-3}.$ The molality of the solution is $... \ m$ [Given that molecular mass of $NaOH = 40 \ g \ mol^{-1}$]

Volume of air required to completely burn $10 \ L$ of $C_2H_4$ is ................ $L$ (assume all volumes are measured at the same temperature and pressure,and air contains $20\%$ oxygen by volume).

In the reaction $2 KClO_{3(s)} \longrightarrow 2 KCl_{(s)} + 3 O_{2(g)}$,$\Delta H^{\circ} = -78 \ kJ$. If $33.6 \ L$ of oxygen gas is liberated at $S.T.P.$,what is the mass of $KCl_{(s)}$ produced (in $g$)? (Atomic mass: $K = 39, Cl = 35.5 \ g \ mol^{-1}$)