Textbook Question 6C.19 Reasoning for Relative Acid Strengths

[Sofia Lucido 3L]

I have a question about parts c) and f) for question 6C.19 in the textbook.

For part c) I said that was the stronger acid because the Br-H bond is longer and therefore weaker than the H-Cl bond in . The textbook said that is stronger and I was wondering if someone could explain why?

Similarly, for part f) I said that was stronger than because the H-Ge bond is longer and weaker than the H-C bond.

For both of these parts can someone explain why and are the stronger acids!

Thank you!

[Jay Solanki 3A]

for part c, there is no bond between the H and Br. The bond in both of the molecules that you are comparing is an O-H bond. Since the bond is the exact same, we look at other aspects of the molecule. Cl is more electronegative than Br, so it has higher electron-withdrawing power, therefore the O-H bond in HClO2 is weaker since the Cl is able to withdraw electrons from this bond greater. Since the O-H bond in HClO2 is weaker, it is going to be the stronger acid, as it is more likely to deprotonate.

The explanation for f is very similar. C is more electronegative than Ge, so the O-H bond in H2CO3 will be weaker, making it the stronger acid. Hope this helps!