EK 2F practice test - Physical Science question #13

[Gauss44]

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How is H2O a stronger base than the Cl ion, Br ion, or I ion? (Cl, Br, and I all have a -1 charge.)

I'm following the CARDIO rules. Are they following the "stronger acid, weaker base" rule? How do you know which set of rules to follow?

 

[QrtrLifeCrisis]

Think about this reaction:

HCl + H2O --> Cl- and H3O+

This reaction and similar ones involving strong acids go almost to completion. Cl- is the conjugate base and H3O+ is the conjugate acid. A reaction will always go strong --> weak. That's how you know H2O is a stronger base than the Cl- base.

Re: negative charge. Just because it has a negative charge doesn't necessarily mean it's a stronger base. NH3 is a stronger base than any of the negatively charged conjugate bases of strong acids because of its lone pair of electrons. The same thing can be said for H2O.

 

[reising1]

How is H2O a stronger base than the Cl ion, Br ion, or I ion? (Cl, Br, and I all have a -1 charge.)

I'm following the CARDIO rules. Are they following the "stronger acid, weaker base" rule? How do you know which set of rules to follow?

Was this a discrete question? If so, that sucks 🙁

Questions like this are difficult and I always feel like I'm guessing

 

[QrtrLifeCrisis]

Was this a discrete question? If so, that sucks 🙁

Questions like this are difficult and I always feel like I'm guessing

I don't see how it's difficult. If you have a basic understanding of acid/bases, this should have been one of the easier concepts.