Equal masses of $H_2, O_2$ and methane have been taken in a container of volume $V$ at temperature $27 \ ^oC$ in identical conditions. The ratio of the volumes of gases $H_2 : O_2 :$ methane would be

One litre oxygen gas at $STP$ will weigh $.................. \ g$

$100 \ mL$ of $H_{2(g)}$ and $100 \ mL$ of $Cl_{2(g)}$ were allowed to react at $1 \ bar$ pressure as: $H_{2(g)} + Cl_{2(g)} \longrightarrow 2 HCl_{(g)}$. What will be the $PV$ type of work done during the reaction?

How much heat change in $kJ$ will occur when $233.0 \, g$ of calcium oxide reacts with sufficient carbon to produce $CaC_2$? The reaction is: $CaO_{(s)} + 3C_{(s)} \to CaC_{2(s)} + CO_{(g)}$; $\Delta H^o = 464.8 \, kJ/mol$.

How many grams of $3-$hydroxypropanal $(MW=74)$ must be dehydrated to produce $7.8 \ g$ of acrolein $(MW=56)$ $(C_3H_4O)$ if the percentage yield is $64\%$? (Round off to the nearest integer).
[Given: Atomic masses: $C = 12.0 \ u, H = 1.0 \ u, O = 16.0 \ u$]

$2 \ g$ of aluminium is treated separately with excess of dilute $H_{2}SO_{4}$ and excess of $NaOH$. The ratio of the volumes of hydrogen evolved is