The value of which of the following units of concentration will not change with the change in temperature?

$A$ certain aqueous solution of $FeCl_3$ (formula mass $= 162 \ g/mol$) has a density of $1.1 \ g/mL$ and contains $20.0 \ \% \ FeCl_3$ by mass. The molar concentration (molarity) of this solution is: (in $M$)

$A$ sample of drinking water was found to be severely contaminated with chloroform $(CHCl_{3})$,supposed to be a carcinogen. The level of contamination was $15$ $ppm$ (by mass).
$(i)$ Express this in percent by mass.
$(ii)$ Determine the molality of chloroform in the water sample.

The density of a solution containing $13 \%$ by mass of $H_2SO_4$ is $1.09 \ g/mL$. The molarity and normality of the solution are respectively :-

Molality of $0.8 \ M \ H_2SO_4$ solution (density $1.06 \ g \ cm^{-3}$) is . . . . . . $\times 10^{-3} \ m$.

The mole fraction of the solute in a $1 \ m$ (molal) aqueous solution is: