Calculate the ph at the equivalence point for the titration of 0.230 m methylamine (ch3nh2) with 0.230 m hcl. the kb of methylamine is 5.0× 10–4.

The pH at the equivalence point for the titration will be 0.65.

Solution:

Let the concentration of be x

Initial concentration of , c = 0.230 M

at eq'm  c-x                         x                    x

Expression of :

Since ,methyl-amine is a weak base,c>>x so .

Solving for x, we get:

Given, HCl with 0.230 M , it dissociates fully in water which means = 0.230 M

will result in neutral solution, since

Remaining after neutralizing ions

The pH at the equivalence point for the titration will be 0.65.