The amount of ammonium sulphate required for the preparation of $1 \, M$ solution in $2 \, L$ is ............ $gm$.

The molality of the solution prepared by dissolving $125 \ mL$ of pure methanol $(d = 0.8 \ g \ mL^{-1})$ in $375 \ g$ of ethanol is

When equal volumes of $0.1 \ M \ AgNO_3$ and $0.2 \ M \ NaCl$ are mixed,the concentration of $NO_3^-$ in the resulting mixture will be ............. $M$.

An aqueous solution contains $28\%$ by weight of a liquid $A$ $(m_w = 140)$. The mole fraction of liquid $A$ is:

The density of '$x$' $M$ solution ('$x$' molar) of $NaOH$ is $1.12 \ g \ mL^{-1}$. While in molality,the concentration of the solution is $3 \ m$ $(3 \ molal)$. Then '$x$' is.
(Given: Molar mass of $NaOH$ is $40 \ g \ mol^{-1}$)

The number of moles of a solute in its solution is $20$ and the total number of moles is $80$. The mole fraction of the solute is: