Question

What would happen if small amounts of 1M HNO₃ were added to a solution of 1M HC₂H₃O₂?

A: The percent ionization of HC₂H₃O₂ will go down.

B: The acid ionization constant for HC₂H₃O₂ will go up.

C: The percent ionization for HC₂H₃O₂ will remain unchanged

D: The percent ionization of HC₂H₃O₂ will go up.

E: The acid ionization constant for HC₂H₃O₂ will go down.

Answer 1

HC2H3O2 dissociates as:
HC2H3O2 + H2O <-> C2H3O2- + H3O+

Since we are adding HNO3 which is H3O+, the above equilibrium will be shifted to the right.

So, percent ionisation of HC2H3O2 will decrease

Acid ionisation constant will not change as it depends only on temperature.

Answer: A