If $1/2 \text{ mole of oxygen reacts with aluminum to form } Al_2O_3, \text{ the mass of aluminum metal consumed in the reaction is } ..... \text{ g. } (Al=27)$

$5 \, L$ 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

What volume in $mL$ of $73 \ g/L$ hydrochloric acid is required to completely neutralize the sodium hydroxide produced by the reaction of $0.46 \ g$ of sodium metal with water?

To obtain the maximum mass of $NO_2$ from a given mass of a mixture of $NH_3$ and $O_2$,the ratio of the mass of $NH_3$ to $O_2$ should be based on the reaction: $NH_3 + O_2 \longrightarrow NO_2 + H_2O$

How many molecules of carbon dioxide are formed when $0.6 \ g$ carbon is burnt in air?

$A$ gas mixture contains $25 \%$ He and $75 \% CH_4$ by volume at a given temperature and pressure. The percentage by mass of methane in the mixture is approximately . . . . . . (in $\%$)