$2.76 \, g$ of silver carbonate on being strongly heated yields a residue weighing $..........$ $g$.

How many moles of ethene are required to prepare $6.0 \ g$ of ethane by the hydrogenation process (in $mole$)?

How many litres of oxygen (at $STP$) are required for complete combustion of $39 \ g$ of liquid benzene?
(Atomic weights: $C=12, O=16, H=1$)

$A$ mixture of gases contains $H_2$ and $O_2$ gases in the ratio of $1 : 4$ $(w/w)$. What is the molar ratio of the two gases in the mixture?

At constant temperature and pressure,the change in volume when $80\%\, 100\, mL$ of phosgene $(COCl_2)$ decomposes into $CO$ and $Cl_2$ is an increase of ............... $mL$.

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