The amount of calcium oxide produced on heating $150 \ kg$ of limestone ($75 \%$ pure) is $........... \ kg$ $(Nearest \ integer)$. Given: Molar mass (in $g \ mol^{-1}$) of $Ca = 40, O = 16, C = 12$.

If $500 \ mL$ of $CaCl_2$ solution contains $3.01 \times 10^{22}$ chloride ions,the molarity of the solution will be: (in $M$)

Excess of $NaOH\, (aq)$ was added to $100\, mL$ of $FeCl_3\, (aq)$ resulting in $2.14\, g$ of $Fe(OH)_3$. The molarity of $FeCl_3\, (aq)$ is (Given molar mass of $Fe=56\, g\, mol^{-1}$ and molar mass of $Cl=35.5\, g\, mol^{-1}$) (in $, M$)

$9.3 \ g$ of aniline is subjected to reaction with excess of acetic anhydride to prepare acetanilide. The mass of acetanilide produced if the reaction is $100 \%$ completed is $x \times 10^{-1} \ g$. Find the value of $x$. (Given molar mass in $g \ mol^{-1}: N: 14, O: 16, C: 12, H: 1$)

Volume of $3 \ M \ NaOH$ (formula weight $40 \ g \ mol^{-1}$) which can be prepared from $84 \ g$ of $NaOH$ is $ . . . . . . \times 10^{-1} \ dm^3$.

$A$ solution of $H_2SO_4$ is $31.4 \%$ $H_2SO_4$ by mass and has a density of $1.25 \ g \ mL^{-1}$. The molarity of the $H_2SO_4$ solution is . . . . . . $M$ (nearest integer) [Given molar mass of $H_2SO_4 = 98 \ g \ mol^{-1}$]