What volume of $2 \,M \,H_2SO_4$ is required to prepare $100 \,mL$ of $0.2 \,N \,H_2SO_4$ solution (in $\,mL$)?

$25 \ mL$ of a solution of $Na_2CO_3$ having a specific gravity of $1.25$ required $32.9 \ mL$ of a solution of $HCl$ containing $109.5 \ g$ of the acid per litre for complete neutralization. Calculate the volume of $0.84 \ N$ $H_2SO_4$ that will be completely neutralized by $125 \ g$ of the $Na_2CO_3$ solution (in $mL$).

Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in $grams$) of the salt required to achieve $10 \; ppm$ of iron in $100 \; kg$ of wheat is
Atomic weight : $Fe = 55.85$,$S = 32.0$,$O = 16.00$

The molarity of liquid $HCl$ with a density equal to $1.17 \ g/cc$ is: (in $M$)

$0.7 \ g$ 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:

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