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

$A$ container contains $4 \ g$ of $H_2$,$4 \ g$ of $He$,and a certain amount of $Ne$ at a certain temperature. What is the mass of $Ne$ required so that the partial pressure exerted by $Ne$ is equal to the partial pressure of $He$ (in $g$)?

$A$ given initial mass of $KClO_3$ on $50\%$ decomposition produces $67.2 \ L$ of oxygen gas at $0 \ ^\circ C$ and $1 \ atm$. The other product of decomposition is $KCl$. The initial mass of $KClO_3$ (in $g$) taken is:

$A$ $250 \, mL$ solution of $Na_2CO_3$ contains $2.65 \, g$ of $Na_2CO_3$. If $10 \, mL$ of this solution is taken and diluted with distilled water up to $0.1 \, L$,what will be the molarity of the resulting solution (in $, M$)?

Calculate the volume of $99 \text{ g}$ of $CO_2$ at $STP$. (in $\text{ L}$)

At $STP$,'$x$' $g$ of a metal hydrogen carbonate $(MHCO_3)$ (molar mass $84 \ g \ mol^{-1}$) on heating gives $CO_2$,which can completely react with $0.2 \ mol$ of $MOH$ (molar mass $40 \ g \ mol^{-1}$) to give $MHCO_3$. The value of '$x$' is