What is the mass of glucose in $500 \ g$ of an aqueous solution of glucose with a molality of $0.5 \ m$?

When $5 \ g$ of acetic acid is dissolved in $1 \ L$ of ethanol,assuming no reaction occurs between them,calculate the molality of the resulting solution. (Density of ethanol = $0.789 \ g/mL$) (in $m$)

If equal weights of $NaCl$ and $KCl$ are dissolved in the same volume of solution,how will the molarity of the two solutions compare?

$25.3 \ g$ of sodium carbonate,$Na_2CO_3$ is dissolved in enough water to make $250 \ mL$ of solution. If sodium carbonate dissociates completely,the molar concentration of sodium ions,$Na^{+}$,and carbonate ions,$CO_3^{2-}$,are respectively:
(Molar mass of $Na_2CO_3 = 106 \ g \ mol^{-1}$)

Explain parts per million (ppm) in brief.

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