Question

What is the acid being titrated that is a weak acid strong base.

a) Sulfamic acid (pKa = 1.05)

b) Chlorous acid (pKa = 1.94)

c) Carbamodithioic acid (pKa = 2.95)

d) 3-bromopropanoic acid (pKa = 4.00)

e) 2,2-dimethylpropanoic acid (pKa = 5.03)

Answer 1

More the k_a ( acid dissociation constant) , stronger the acid .

Thus , less the k_a ( acid dissociation constant) , weaker the acid .

Now ,

Thus , less the k_{a ,} more the pk_a , weaker the acid.

In your given list , the order of pk_a

e>d>c>b>a

Thus strength of acid ,

a>b>c>d>e

So , e is the weakest one and a is the strongest one .

So , the best choice of acid for weak acid strong base titration is -

e (2,2-dimethylpropanoic acid)