What is the meaning of concentration of a solution? Discuss the different ways to express the concentration of solutions.

(N/A) The concentration of a solution is defined as the amount of solute present in a given quantity (either volume or mass) of the solution or solvent.
Different methods to express concentration include:
$1$. Molarity $(M)$: Moles of solute per liter of solution.
$2$. Molality $(m)$: Moles of solute per kilogram of solvent.
$3$. Normality $(N)$: Gram equivalent of solute per liter of solution.
$4$. Mole fraction $(x)$: Ratio of moles of one component to the total moles of all components.
$5$. Mass percentage $(\% w/w)$: Mass of solute in $100 \ g$ of solution.
$6$. Volume percentage $(\% v/v)$: Volume of solute in $100 \ mL$ of solution.
$7$. Parts per million $(ppm)$: Parts of solute per million parts of solution.