$0.1 \ mol$ of $NaCl$ is dissolved in $100 \ g$ of water. The mole fraction of $NaCl$ is

Which of the following concentration terms does not change with a change in temperature?

$A$ commercially sold concentrated $HCl$ is $35 \%$ $HCl$ by mass. If the density of this commercial acid is $1.46 \ g/mL$,the molarity of this solution is $....M$.
(Atomic mass : $Cl = 35.5 \ amu, H = 1 \ amu$)

The molality of a $10\%\ (v/v)$ solution of di-bromine in $CCl_4$ (carbon tetrachloride) is $x$. $x = ...... \times 10^{-2}\ m$. (Nearest integer)
[Given : molar mass of $Br_2 = 160\ g\ mol^{-1}$
atomic mass of $C = 12\ g\ mol^{-1}$
atomic mass of $Cl = 35.5\ g\ mol^{-1}$
density of dibromine $= 3.2\ g\ cm^{-3}$
density of $CCl_4 = 1.6\ g\ cm^{-3}$]

$x$ grams of water is mixed in $69 \ g$ of ethanol. The mole fraction of ethanol in the resultant solution is $0.6$. What is the value of $x$ in grams?

If a substance $A$ dissolves in a solution of a mixture of $B$ and $C$ with their respective number of moles as $n_A, n_B$ and $n_C$,the mole fraction of $C$ in the solution is: