What is the weight of oxygen required for the complete combustion of $2.8 \, kg$ of ethylene? (in $kg$)

If the density of iron is $7.86 \, g \, cm^{-3}$ and its atomic mass is $55.85 \, u$,then find the volume occupied by $1 \, mol$ of iron atoms in $cm^{3}$.

$10 \ mL$ of $1 \ M$ $H_2SO_4$ will completely neutralize:

In the complete combustion of $C_4H_{10}$,the number of moles of oxygen required is:

$A$ mixture of dihydrogen and dioxygen at $1 \ bar$ pressure contains $20 \%$ by weight of dihydrogen. Calculate the partial pressure of dihydrogen. (in $bar$)

The number of moles of hydrogen molecules required to produce $20$ moles of ammonia through Haber's process is