Question

(A) when the concentration of a solute is less than its solubility, the solution is said to be ___ with that solute.(B) which is most soluble in water? CH₄, CCl₄, CHCL₃, CF₄ (C) Considering ammonium chloride, cyclohexane, methanol, and ethylene glycol (HOCH₂CH₂OH), which will be most soluble in pentane? ammonium chloride, cyclohexane, methanol or ethylene glycol?

Answer 1

A) when the concentration of a solute is less than its solubility, the solution is said to be unsaturated with that solute.

Reason

Unsaturated solution is the one which can dissolve more solute. As the solublity of the solute is more, it has tendency to dissolve in large amount in the dolvent. But, when solute is in less amount, the solution is unsaturated

B) CHCl₃ is the most soluble in water.

Reason: like dissolves like i. e. Polar compounds are soluble in polar solvents and non- polar compounds are soluble in non-polar solvents. Water is a polar solvent, so a polar molecule is soluble in it.

CH₄,CCl₄,CF₄ molecules are symmetrical structure. The individual dipole moments cancel out on account of symmetry of the molecules. Thus, the net dipole moment is zero.

However, CHCl₃ is not symmetrical as all atoms are not same. Therefore, the net dipole moment is non-zero. In comparison to other molecules, it is soluble in water.

C) pentane is a non-polar solvent so non-polar molecule cyclohexane is soluble in it.

Methanol and ethylene glycol are less soluble in pentane but more soluble in water.

Methanol, a monohydric alcohol, (CH₃OH) is polar due to the presence of polar OH group. Ethylene glycol is more polar than methanol because of the presence of 2 polar OH groups. Structure of ethylene glycol - a dihydric alcohol HOH₂C-CH₂OH

Ammonium chloride is a polar compound as ammonium is a positively charged species and a chloride is a negatively charged species. So, it is insoluble in non polar solvent pentane.