The molecular weight of a gas is $45$. Its density at $STP$ is

What is the volume (in $dm^3$) occupied by $75 \ g$ of ethane at $S$.$T$.$P$.?

How much volume of water is to be added to dilute $10 \, mL$ of $10 \, N \, HCl$ to make it decinormal? .............. $mL$

What volume of $0.1 \, M \, H_2SO_4$ is required to completely neutralize $40 \, mL$ of $0.2 \, M \, NaOH$?

What is the mass of $33.6 \ dm^3$ of methane gas at $S.T.P.$?

When $CO_2\,(g)$ is passed over red hot coke,it partially gets reduced to $CO\,(g).$ Upon passing $0.5\,L$ of $CO_2\,(g)$ over red hot coke,the total volume of the gases increases to $700\,mL.$ The composition of the gaseous mixture at $STP$ is