If $2 \ g$ of $NaOH$ is dissolved to make $200 \ mL$ solution at $25^{\circ} C$, the molarity $(M)$ at $90^{\circ} C$ is

Some amount of dichloromethane $(CH_2Cl_2)$ is added to $671.141 \ mL$ of chloroform $(CHCl_3)$ to prepare a $2.6 \times 10^{-3} \ M$ solution of $CH_2Cl_2$ $(DCM)$. The concentration of $DCM$ is $......... \ ppm$ (by mass). Given: Atomic mass: $C = 12, H = 1, Cl = 35.5$; density of $CHCl_3 = 1.49 \ g \ cm^{-3}$.

What is the mole fraction of the solute in a $2.5 \, m$ aqueous solution?

$25 \ mL$ of $3.0 \ M \ HNO_3$ are mixed with $75 \ mL$ of $4.0 \ M \ HNO_3$. If the volumes are additive,the molarity of the final mixture would be ......... $M$.

What is the molarity of a solution containing $3.2 \ g$ of $NaOH$ (molar mass $40 \ g \ mol^{-1}$) in $250 \ cm^{3}$ of water?

If one mole of a substance is present in $1 \ kg$ of solvent,then