When equal volumes of $0.1 \ M \ AgNO_3$ and $0.2 \ M \ NaCl$ are mixed,the concentration of $NO_3^-$ in the resulting mixture will be ............. $M$.

If $120 \, g$ of urea (molar mass = $60 \, g/mol$) is dissolved in $1000 \, g$ of water and the density of the resulting solution is $1.15 \, g/mL$,what is the molarity of the solution in $M$?

What mass of ethanol in $g$ must be added to $1.0 \, kg$ of water to have a mole fraction of ethanol equal to $0.2$?

$A$ sample of drinking water is found to be severely contaminated with chloroform $(CHCl_3)$,which is a suspected carcinogen. If the level of contamination is $15 \ ppm$ (by mass),express this in percentage by mass.

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

If $5.85 \ g$ of $NaCl$ is dissolved in $72 \ g$ of water,find the mole fraction of $NaCl$.