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).

If the density of methanol is $0.793 \ kg \ L^{-1}$,what volume is needed to prepare $2.5 \ L$ of a $0.25 \ M$ solution (in $mL$)?

How many moles of $H_2O$ are liberated when one mole of hydrated $MgCl_2$ is heated?

If a mixture of $340 \ g$ of $N_2$ and $H_2$ in the stoichiometric ratio yields $20\%$ $NH_3$ by mass,what is the mass of $NH_3$ produced in $g$?

$20 \ mL$ of methane is completely burnt using $50 \ mL$ of oxygen. The volume of the gas left after cooling to room temperature is (in $mL$)

$A$ 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 $M$)