How many moles of methane are required in the combustion reaction of methane to produce $22 \ g$ of $CO_{2(g)}$ (in $mol$)?

The conversion of oxygen to ozone occurs to the extent of $15\%$ only. The mass of ozone that can be prepared from $67.2 \ L$ of oxygen at $1 \ atm$ and $273 \ K$ will be ............ $g$.

$1.0 \ g$ of pure calcium carbonate was found to require $50 \ mL$ of dilute $HCl$ for complete reaction. The strength of the $HCl$ solution is given by ........ $N$.

What volume of $0.8 \ M$ solution contains $0.1 \ mole$ of the solute? (in $mL$)

If $1 \, mole$ of $H_3PO_x$ is completely neutralized by $80 \, g$ of $NaOH$,select the correct statement :-

$100 \, mL$ of $0.1 \, N \, HCl$ is neutralized by $0.2 \, N \, NaOH$ solution. After adding $30 \, mL$ of $NaOH$ solution,the neutralization is continued using $0.25 \, N \, KOH$. Calculate the volume of $KOH$ in $mL$ required to complete the neutralization.