The number of moles of $KCl$ in $1000 \ mL$ of $3 \ M$ solution is

$A$ $40 \%$ by mass sucrose solution is heated till it becomes $50 \%$ by mass. Calculate the mass of water lost from $100 \ g$ of the solution. (in $g$)

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 $40 \ g \ mol^{-1}$)

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

In a water sample,the concentration of $F^-$ ions is $10 \ ppm$ by weight-volume. What is the concentration of $F^-$ in $\% W/V$ in that solution?

At $T \ (K)$,$100 \ g$ of $98\%$ $H_2SO_4$ $(w/w)$ aqueous solution is mixed with $100 \ g$ of $49\%$ $H_2SO_4$ $(w/w)$ aqueous solution. What is the mole fraction of $H_2SO_4$ in the resultant solution?
(Given: Atomic mass $H = 1 \ u; S = 32 \ u; O = 16 \ u$)
(Assume that temperature after mixing remains constant)