What type of solution is an alloy?

To what extent must a given solution of concentration of $40 \, mg$ silver nitrate per $mL$ be diluted to yield a solution of concentration of $16 \, mg$ $AgNO_3$ per $mL$?

What will be the mass percentage of an aqueous solution of $NaOH$ in which the mole fraction of $NaOH$ is $0.2$ (in $\% W/W$)?

An aqueous solution of urea containing $18 \ g$ of urea in $1500 \ cm^{3}$ of the solution has a density of $1.052 \ g/cm^{3}$. If the molecular weight of urea is $60$,the molality of the solution is: (in $m$)

The weight percent of sucrose (formula weight $= 342 \, g \, mol^{-1}$) in an aqueous solution is $3.42$. The density of the solution is $1 \, g \, mL^{-1}$. The concentration of sucrose in the solution in $mol \, L^{-1}$ is

$4.5 \ g$ of compound $A$ $(MW = 90)$ was used to make $250 \ mL$ of its aqueous solution. The molarity of the solution in $M$ is $x \times 10^{-1}$. The value of $x$ is ............ (Rounded off to the nearest integer)