Question

A salt that could decrease the ionization of HCOl in soln is probably
a. NaOH
b. NaCl
c. NaOCl
d. NaH
e. none of these

how would you solve this

Answer 1

First, I would look in my books and try to figure out what the heck HCOI is? I assume this is HOCl, hypochlorous acid.
Look at the ionization equation, since that's what the question is about.
HOCl ==> H^+ + OCl^-

Now look at the possibilities.
a. Add NaOH. That reacts with H^+ to form water, removing water shifts the equilibrium to the right which increases and not decreases the ionization so a can't be right.

b. NaCl has no effect on anything.

c. NaOCl is a salt that ionizes to produce Na^+ and OCl^-. The addition of OCl forces the equilibrium to the left which means less ionization and that's what we want so I pick c.

d. NaH.This gives us the hydride ion (H^-) in solution which will combine with H^+ to form H2. That removes H^+ from solution, the reaction shifts to the right, that's more ionization and not less so we don't pick d.