For the following reaction, which reactant functions as an acid?
A) I
B) II
C) III
D) IV
E) none of the above

Question

For the following reaction, which reactant functions as an acid? 
A) I 
B) II 
C) III 
D) IV 
E) none of the above

Quizplus · Accepted Answer

In order for a reactant to function as an acid, it must donate a proton (H+). In this reaction, reactant II - HCl - can donate a proton to reactant I - Na2SO3 - and thus functions as an acid. The other reactants (I, III, and IV) either do not contain a hydrogen atom capable of donation or do not have a suitable electron pair to accept a proton.

For the Following Reaction, Which Reactant Functions as an Acid