Consider the structure of sodium benzoate,NaOC(O) Ph,the sodium salt of benzoic acid.In which of the following solvents would you predict sodium benzoate to be soluble?
IWater,H₂O
IIPentane,CH₃(CH₂) ₃CH₃
IIIDiethyl ether,(CH₃CH₂) ₂O
IVMethanol,CH₃OH
VAcetone,CH₃C(O) CH₃

Question

Quizplus · Accepted Answer

Sodium benzoate is a polar molecule due to the presence of a carboxylate group (-COO-) and is therefore expected to dissolve in polar solvents. Among the given options, water (I) and methanol (IV) are polar solvents and hence, sodium benzoate is expected to be soluble in both of them. Diethyl ether (III) is also a polar solvent and has a dipole moment of 1.15 D. Acetone (V) is a polar aprotic solvent and has a dipole moment of 2.88 D. However, pentane (II) is a nonpolar solvent and hence, sodium benzoate is not expected to be soluble in it. Therefore, the best choice(s) are options I and IV, and the correct answer is C.

Consider the Structure of Sodium Benzoate,NaOC(O)Ph,the Sodium Salt of Benzoic