Creating a buffer using a diprotic acid (strong)?

[510586]

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Hi everyone. So normall when creating a buffer we can use a weak acid and weak base, strong acid and weak base (2 times the amount), and weak acid (2 times amount) and strong base. If we were to use say H2SO4 (strong acid), would we have to have 4 times the weak base to make a normal buffer?

 

[Jay20155555]

I could be wrong but I dont think it will be 4 times the weak base because the second hydrogen only dissociates partially, so I dont think it will change it much.

BUT to add another question to this......

What if we have an example with a group 2 metal hydroxide (as we know will have both OH completely dissociate) then would it be 4 times as much if we have a weak acid with a strong base like Ba(OH)2?

 

[510586]

I could be wrong but I dont think it will be 4 times the weak base because the second hydrogen only dissociates partially, so I dont think it will change it much.

BUT to add another question to this......

What if we have an example with a group 2 metal hydroxide (as we know will have both OH completely dissociate) then would it be 4 times as much if we have a weak acid with a strong base like Ba(OH)2?

Yea hopefully someone answers both of these types of questions.

 

[Jay20155555]

yea hopefully, and im still a little confused on the 3 types of buffers.... From chads vid he says they are

1) weak acid and conj base
2) weak acid and strong base
3) weak base and strong acid

but arent 1 and 2 the same thing?

 

[510586]

yea hopefully, and im still a little confused on the 3 types of buffers.... From chads vid he says they are

1) weak acid and conj base
2) weak acid and strong base
3) weak base and strong acid

but arent 1 and 2 the same thing?

No one is a 1:1 ratio the other is a 2:1 ratio. They end up creating the same thing (1:1 weak acid and conjugate base) but are 2 different ways of creating it.

 

[Jay20155555]

in weak acid and conj base what does the weak acid react with? water?

 

[510586]

No I think it just starts out with the 2 alone. In my chad notes he didn't react anything for the weak weak combo whereas in the weak strong combos he reacts them to make water and conjugate base or salt and conjugate acid. Hopefully someone can clarify this.