To change the strength of $25 \, mL$ of $0.15 \, M$ $HCl$ to $0.1 \, M$,the quantity of water that is to be added is.......$mL$

Formation of polyethylene from calcium carbide takes place as follows:
$CaC_2 + 2H_2O \to Ca(OH)_2 + C_2H_2$
$C_2H_2 + H_2 \to C_2H_4$
$n(C_2H_4) \to (-CH_2-CH_2-)_n$
The amount of polyethylene obtained from $64.1 \ kg$ of $CaC_2$ is......$kg$.

$20 \ mL$ of methane is completely burnt using $50 \ mL$ of oxygen. The volume of the gas left after cooling to room temperature is (in $mL$)

The volume of $0.1 \, N$ dibasic acid sufficient to neutralize $1 \, g$ of a base that furnishes $0.04 \, mole$ of $OH^{-}$ in aqueous solution is ............ $mL$

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: $K = 39, Cl = 35.5 \ g \ mol^{-1}$)

$150 \ g$ $CaCO_3$ sample was taken. On its complete decomposition $56 \ g$ $CaO$ is produced. The $\%$ purity of the sample is .............. $\%$