WAEC Chemistry 2011 Paper

Concept:A molar solution is defined by its concentration of exactly $1\ \mathrm{mol\,dm}^{-3}$.Explanation:In chemistry, a molar solution contains one mole of solute dissolved in one cubic decimetre of solution.Thus, its concentration is $1\ \mathrm{mol\,dm}^{-3}$.Option D matches this definition precisely.Option A is wrong because a molar solution is not necessarily supersaturated.Option B describes a saturated solution, not a molar solution.Option C is incorrect because a molar solution has a fixed amount of solute, not any amount.Therefore, the correct statement is the one that specifies one mole of solute in $1\ \mathrm{dm}^3$ of solution.Answer:D. contains one mole of the solute in $1\ \mathrm{dm}^3$ of solution