$4 \ g$ of $NaOH$ is dissolved in $250 \ mL$ of water to prepare a solution. Find the molarity of the solution. (in $M$)

$10 \ g$ of a solute is dissolved in $90 \ g$ of a solvent. Its mass percent in solution is

What will be the molality of the solution containing $18.25 \ g$ of $HCl$ gas in $500 \ g$ of water (in $m$)?

What is meant by the concentration of a solution?

The mole fraction of ethanol in water is $0.08$. Its molality is

$34.2 \ g$ of sugar is dissolved in $1.8 \times 10^{2} \ g$ of water to form sugar syrup. Calculate the mole fraction of sugar. (Molar mass of sugar $= 342 \ g/mol$,water $= 18 \ g/mol$)