In the combustion of $2.0 \ g$ of methane,$25 \ kcal$ of heat is liberated. The heat of combustion of methane would be ..... $kcal$.

What quantity of ammonium sulphate is necessary for the production of $NH_3$ gas sufficient to neutralize a solution containing $292 \ g$ of $HCl$? $(HCl=36.5, (NH_4)_2SO_4=132, NH_3=17)$

Equal masses of ethane $(C_2H_6)$ and hydrogen $(H_2)$ are mixed in an empty container at $298 \ K$. The fraction of total pressure exerted by hydrogen is:

How many litres of $CO_2$ at $STP$ will be formed when $100 \ mL$ of $0.1 \ M \ H_2SO_4$ reacts with excess of $Na_2CO_3$?

Magnetite can be reduced with $CO$ to yield iron metal and carbon dioxide. Calculate the mass of magnetite (in $kg$) needed to obtain $4 \ kg$ of iron if the process is $80 \%$ efficient. [Atomic weight of $Fe$ and $O$ are $56 \ g$ and $16 \ g$, respectively]

$A$ sample of nitric acid has a density of $1.41 \ g \ mL^{-1}$ and the mass percentage of nitric acid is $69 \%$. Calculate the concentration of nitric acid in the sample in moles per liter. (in $M$)