$1000 \ g$ aqueous solution of $CaCO_3$ contains $10 \ g$ of carbonate. Concentration of the solution is .......... $ppm$.

Calculate the molarity of $NaOH$ in the solution prepared by dissolving $4 \,g$ of it in enough water to form $250 \,mL$ of the solution. (in $,M$)

The molality of an aqueous solution of any solute having a mole fraction of $0.25$ is . . . . . . . (in $m$)

The molarity of a $70 \%$ (mass/mass) aqueous solution of a monobasic acid $(X)$ is $........... \ M$ (Nearest integer). Given: Density of aqueous solution of $(X)$ is $1.25 \ g \ mL^{-1}$,Molar mass of the acid is $70 \ g \ mol^{-1}$.

The concentration of $1 \ L$ of $CaCO_3$ solution is $1000 \ ppm$. What is its concentration in $mol \ L^{-1}$ ?
$(Ca=40 \ u, O=16 \ u, C=12 \ u)$

The density of a $2.05 \ M$ solution of acetic acid $(CH_3COOH)$ in water is $1.02 \ g \ mL^{-1}$. The molality of the solution is ......... $mol \ kg^{-1}$.