What is $\Delta n$ for the combustion of $1 \ mole$ of benzene,when both the reactants and the products are in the gaseous state at $298 \ K$?

$10 \ mL$ of an aqueous solution containing $222 \ mg$ of calcium chloride $(mol. wt. = 111)$ is diluted to $100 \ mL$. The concentration of chloride ion in the resulting solution is $..... \ mol/L$.

How many $g$ of bromine will react with $21\, g$ of $C_3H_6$?

$25 \ mL$ 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 $mL$).

In an aqueous solution of $A_2B_3$,it undergoes complete ionization according to the reaction $A_2B_3 \rightleftharpoons 2A^{+3} + 3B^{-2}$. The concentration of $A^{+3}$ is equal to......

$A$ bottle of cold drink contains $200 \ mL$ liquid in which $CO_2$ is $0.1 \ M$. Suppose $CO_2$ behaves like an ideal gas,the volume of the dissolved $CO_2$ at $STP$ is (in $L$)