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

Given that $N_{2(g)} + 3 H_{2(g)} \longrightarrow 2 NH_{3(g)}$; $\Delta_r H^{\circ} = -92 \ kJ$, the standard molar enthalpy of formation in $kJ \ mol^{-1}$ of $NH_{3(g)}$ is

The active mass of benzene $(C_6H_6 = 78)$ with a density of $1.56 \, g/mL$ is .......

For the combustion reaction of $1 \ mol$ of benzene,if all reactants and products are in the gaseous state,then $\Delta n_{(g)}$ is equal to ......

$0.5 \ M$ of $H_2SO_4$ is diluted from $1 \ L$ to $10 \ L$,the normality of the resulting solution is ......... $N$.

When $5 \ L$ of a gas mixture of methane and propane is perfectly combusted at $0 \ ^\circ C$ and $1 \ atm$,$16 \ L$ of oxygen at the same temperature and pressure is consumed. The amount of heat released from this combustion in $kJ$ ($\Delta H_{comb.} (CH_4) = 890 \ kJ \ mol^{-1},$ $\Delta H_{comb.} (C_3H_8) = 2220 \ kJ \ mol^{-1}$) is