[Caustikola]

How does the addition of an electron withdrawing group increase the acidity of an aliphatic acid?
Eg.
For CH3COOH; pKa=4.76
For FCH2COOH;pKa=2.66
For ClCH2COOH;pKa=2.86
I've tried to take the electronegativities of the Halide atoms into consideration, but in the end the molecules ionize like:
FCH2COOH+H2O<--->FCH2COO- + H3O+
In this instance, How does the substition of a hydrogen atom with a fluorine atom affect the strenght of the O-H Bond?
Any replies will be greatly appreciated

[Guitarmaniac86]

What does a lower pKa tell you?

The electronegativities of the halides go some way to explaining it, think about what the halides are doing to the electrons around the carboxylate group.