Final answer:
option b,An aqueous solution of NaCN is expected to be basic because it is derived from a weak acid (HCN) and a strong base (NaOH), with the resultant CN- ions hydrolyzing to produce OH- ions.
Step-by-step explanation:
Predicting whether a salt will create an acidic, basic, or neutral solution involves considering the acid and base from which the salt is derived. In the case of NaCN, it is made from the weak acid HCN (hydrocyanic acid) and the strong base NaOH (sodium hydroxide).
When NaCN dissolves in water, the CN- ions (the conjugate base of HCN) will hydrolyze to form a small amount of HCN and OH- (hydroxide ions), which makes the solution basic because of the presence of these extra hydroxide ions. Sodium ions, Na+, are the conjugate acid of a strong base (NaOH) and do not affect the acidity of the solution. Therefore, an aqueous solution of NaCN is expected to be basic.