What is molarity?

$A$ molar solution is one that contains one mole of a solute in

For a solution containing $0.03659 \ g/mL$ of $HCl$ and a solution containing $0.04509 \ g/mL$ of acetic acid $(CH_3COOH)$,which of the following is true?

An antifreeze solution is prepared from $222.6 \ g$ of ethylene glycol $(C_2H_6O_2)$ and $200 \ g$ of water. Calculate the molality of the solution. If the density of the solution is $1.072 \ g \ mL^{-1}$,then what shall be the molarity of the solution?

$25.3 \ g$ 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 $Na_2CO_3 = 106 \ g \ mol^{-1}$)

If a solution of methyl alcohol $(CH_3OH)$ is $5.2 \ m$ (molal) in water,what is the mole fraction of methyl alcohol in the solution?