Question #f6709

1 Answer
Jun 4, 2016

Answer:

See explanation below:

Explanation:

When comparing two acids , we look at their conjugate bases stabilities and compare them.

A strong acid will give a stable conjugate base , so the reaction is favoured in the forward direction (acid dissociation).

For #HF#:

#HF->H^(+)+underbrace(F^(-))_("conjugate base")#

For #CH_4#:

#CH_4->H^(+)+underbrace(CH_3^(-))_("conjugate base")#

Looking at both conjugate bases, we can see that the negative charge is carried by fluorine for #F^(-)# and by the carbon atom of #CH_3^(-)#.

Since fluorine is a more electronegative than carbon atom, the negative charge will be more stabilized on fluorine and thus #F^(-)# is a more stable conjugate base than #CH_3^(-)#.

Therefore, #HF# is a stronger acid than #CH_4#.