Question

Which of the following is a weak base in aqueous solution 

A. NH₃ 

B. HCl 

C. KOH 

D. NaOH 

E. Ca(OH)₂

Answer 1

Correct option (A) NH₃ 

Explanation:

HCl is a strong acid, along with HNO₃, H₂SO₄, HBr, HI, and HClO₄. The strong bases include those from the alkali metals (NaOH, LiOH, KOH, RbOH, and CsOH) and the alkaline earth metals (Ca(OH)₂, Sr(OH)₂, and Ba(OH)₂). These appear in Responses C, D, and E. This leaves the weak base ammonia, Response A.