Methylation of $10 \ g$ of benzene gave $9.2 \ g$ of toluene. Calculate the percentage yield of toluene $......$. (Nearest integer)

Consider the complete combustion of butane. The amount of butane utilized to produce $72.0 \ g$ of water is $.... \times 10^{-1} \ g$ (in nearest integer).

What is the volume occupied by $2 \ g$ of helium gas at $STP$ (in $dm^3$)? (molar mass of helium gas $= 4 \ g \ mol^{-1}$)

The mass percentage composition of dry air at sea level is approximately $N_2: 63 \%$, $O_2: 16 \%$, $Kr: 21 \%$. If the total pressure is $p \ atm$, calculate the partial pressure of each component respectively. (Molecular weights: $N_2 = 28, O_2 = 32, Kr = 84$)

For per gram of reactant,the maximum quantity of $N_2$ gas is produced in which of the following thermal decomposition reactions? (Given: Atomic wt. : $Cr = 52 \ u, Ba = 137 \ u$).

$5 \, L$ of a gaseous mixture of ethane and propane are burnt to produce total $11 \, L$ of $CO_2$. Volume percent of $C_2H_6$ in the initial mixture is