Q13.7 P - Chemistry: Molecular Nature Of Matter And Change

Question

Which gives the more concentrated solution, 

(a)${\mathbf{KNO}}_{\mathbf{3}}$ In  ${\mathbf{H}}_{\mathbf{2}}\mathbf{O}$or

(b) ${\mathbf{KNO}}_{\mathbf{3}}$ in carbon tetrachloride $\left({\mathbf{CCl}}_{\mathbf{4}}\right)$? Explain.

Step-by-Step Solution

Answer

${\mathrm{KNO}}_3$ In ${\mathrm{H}}_2\mathrm{O}$ will give a more concentrated solution than  ${\mathrm{KNO}}_3$ in carbon tetrachloride.

Step 1: Check the polarity of both solvent and solute

A more concentrated solution means more solute has been dissolved in the solvent. And basic rule behind dissolution is like dissolution like which means a polar solute will be dissolved in a polar solvent and vice versa.

${\mathrm{KNO}}_3$ is an ionic salt, which means it is polar in nature Carbon tetrachloride is nonpolar in nature and water is polar in nature.

Step 2: More solubility, more concentrated the solution

${\mathrm{KNO}}_3$ being a polar compound will dissolve more in polar solvent i.e., water. Potassium nitrite is not soluble in non-polar carbon tetrachloride. Because ${\mathrm{KNO}}_3$ dissolves to a greater degree in water, it will form a more concentrated solution.