ugh, cant figure which are right.?

Question

which of the following statements are true?


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

b) For an acid H-A : the stronger 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 HClO

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


im having a hard time finding answers in the book, if someone knows something i dont

Answer 1

a) True. The more electronegative the A, the more it will pull the bond electrons closer to it and the easier it will dissociate.

b) False. The stronger the bond the more difficult it is to break, thus the weaker the acid.

c) True. Although Br is less electronegative, it is bigger in size, so the negative charge of the Br- ion is better stabilized making it a weaker base than F- and thus the conjugate acid HBr stronger. You should be careful because for binary acids of elements of the same group the size factor wins over the electronegativity factor.

d)True. You have more O atoms in H2SO4 which stabilize the negative charge in the conjugate base better because of the electronegativity of O but also because you have more resonance structures.

e)False. Now the acids are not binary, so the electronegativity factor wins: Cl is more electronegative thus the ClO group is better at pulling the electrons than the ClO group and therefore HClO is stronger

f) False. It is the other way around. The more electronegative the atoms the more they stabilize the charge of the conjugate base (the anion) or if you prefer, the more the O-H bond is polarized and thus the easier it breaks into O- and H+.

Answer 2

answer C is right