What is the volume of $4.4 \ g$ of $CO_2$ at $STP$ in $L$?

$30.0 \ mL$ of the given $HCl$ solution requires $20.0 \ mL$ of $0.1 \ M$ sodium carbonate solution for complete neutralisation. What is the volume of this $HCl$ solution required to neutralise $30.0 \ mL$ of $0.2 \ M$ $NaOH$ solution (in $mL$)?

What is the percentage atom economy when the formula weight of the desired product is $65 \text{ u}$ and the sum of the formula weights of all reactants is $130 \text{ u}$ (in $\%$)?

$X \ g$ of $Ag$ is dissolved in $HNO_3$ and this solution is treated with excess $NaCl$. If $2.87 \ g$ of $AgCl$ precipitate is obtained,then the value of $X$ is ............. $g$.

Calculate the concentration of nitric acid in moles per litre in a sample which has a density of $1.41 \, g \, mL^{-1}$ and the mass percent of nitric acid in it is $69 \%$.

$0.7 \ g$ of $Na_2CO_3 \cdot xH_2O$ were dissolved in water and the volume was made to $100 \ mL$. $20 \ mL$ of this solution required $19.8 \ mL$ of $N/10 \ HCl$ for complete neutralization. The value of $x$ is: