Answer : The concentration of the
is, 0.209 M
Explanation :
Using neutralization law,

where,
= basicity of an acid
= 2
= acidity of a base (NaOH) = 1
= concentration or molarity of
= 0.220 M
= concentration or molarity of NaOH = ?
= volume of
= 11.9 ml
= volume of NaOH = 25.0 ml
Now put all the given values in the above law, we get the concentration of the
.


Therefore, the concentration of the
is, 0.209 M