which of the following statements are true?

Question

a) For an acid H-O-A : the greater the electronegativity of A, the weaker the acid HA

b) For an acid H-A : the weaker the H-A bond, the stronger the acid H-A

c) HBr is a stronger acid than HF

d) H2SO3 is a weaker acid than H2SO4

e) HBrO is a stronger acid than HIO

f) For carboxylic acids : the smaller the electronegativities of the atoms in the group bonded to the carboxyl group, the stronger the acid

Answer 1

When you compare 2 acids, the stronger one will be able to give away its H+ more easily. That means that the conjugate base will be weaker.

OR if we reverse the reasoning, the more stable the conjugate base is, the more reluctant it will be to react and ake up a H+ (weaker base) so the acid will be stronger.

Electronegative elements will stabilize the anion (the conjugate base), making it more stable and thus making the base weaker and the acid stronger.
So (a) is false
(b) is true. The weaker the H-A bond the easier it will breake
(c) F is more electronegative so HF is stronger acid. Thus it is false
(d) is true. You have more electronegative O (4 instead of 3) in H2SO4, which stabilize more the conjugate bases HSO4(-) and SO4(-2)
(e) is true because Br is more electronegative than I
(f) is false.