What is the volume occupied by $2 \ g$ of helium gas at $STP$ (in $dm^3$)? (molar mass of helium gas $= 4 \ g \ mol^{-1}$)

Equal weights of ethane and hydrogen are mixed in an empty container at $25^{\circ} C$. The fraction of total pressure exerted by hydrogen is

$5 \, N$ $H_2SO_4$ was diluted from $1 \, L$ to $10 \, L$. The normality of the solution obtained is.....$N$.

The volume of $O_2$ required for the complete combustion of $5$ moles of propane $(C_3H_8)$ at $25$ $^\circ C$ is ............... liters.

Calculate the mass of sodium acetate $(CH_{3}COONa)$ required to make $500 \,mL$ of $0.375 \,M$ aqueous solution. Molar mass of sodium acetate is $82.0245 \,g \,mol^{-1}$.

What is the amount of water formed by combustion of $1.6 \ g$ methane (in $g$)?