At $STP$,the volume of $4.4 \, g$ of an unknown gas is $2.24 \, L$. Which of the following is this gas?

$H_2$ evolved at $STP$ on complete reaction of $27 \ g$ of Aluminium with excess of aqueous $NaOH$ would be $............ \ L$

How many moles of $NaOH$ are present in $27 \, mL$ of $0.15 \, M \, NaOH$?

$17.0 \ g$ of $NH_3$ completely vaporizes at $-33.42^{\circ}C$ and $1 \ bar$ pressure,and the enthalpy change in the process is $23.4 \ kJ \ mol^{-1}$. The enthalpy change for the vaporization of $85 \ g$ of $NH_3$ under the same conditions is $..... \ kJ$.

$A$ gas weighing $2.4 \ g$ has a vapor density of $11.2$. What is its volume in $L$ at $STP$?

Amount of oxygen required for combustion of $1 \, kg$ of a mixture of butane and isobutane is ............. $kg$.