Which of these neutralization reactions has a ph < 7 when equal molar amounts of acid and base are mixed. select one:

a. ch3co2h (aq) + naoh (aq) ⇌ h2o (l) + nach3co2 (aq)

b. hcl (aq) + c5h5n (aq) ⇌ c5h5nhcl (aq)

c. h2so4 (aq) + 2 koh (aq) ⇌2 h2o (l) + k2so4 (aq)

d. hcl (aq) + naoh (aq) ⇌ h2o (l) + nacl (aq) ?

The correct answer is B.

Strong acids completely dissociates to give hydrogen ions. Weak bases can only partially dissociate to give hydroxide ions.

Therefore when equal amounts of acid and base are mixed, while Acid is completely dissociated and gives out hydrogen ions but base only gives out a fraction of hydroxide ions.

Therefore number of hydrogen ions in the solution will be higher than hydroxide ions, resulting in an acidic pH. Therefore pH <7