Calculate the mole fraction of ethylene glycol $(C_{2}H_{6}O_{2})$ in a solution containing $20\%$ of $C_{2}H_{6}O_{2}$ by mass.

When $1.04 \ g$ of $BaCl_2$ is dissolved in $10^5 \ g$ of water,what will be the concentration of the solution in $ppm$?

$450 \ mg$ of glucose is dissolved in $100 \ g$ of solvent. What is the molality of the solution (in $m$)?

The molality of $648 \ g$ of pure water is ........... $m$.

$250 \, mL$ of a sodium carbonate solution contains $2.65 \, g$ of $Na_2CO_3$. If $10 \, mL$ of this solution is diluted to $1 \, L$,what is the concentration of the resultant solution? (Molecular weight of $Na_2CO_3 = 106$)

$A$ solution of $H_2O_2$ used for hair bleaching contains approximately $5.0 \ g$ of $H_2O_2$ per $100 \ mL$ of solution. If the molar mass of $H_2O_2$ is $34 \ g/mol$,what is the molarity of this solution?