Can anyone explain to me the concept behind sulfuric acid, as to whether it is a strong or weak acid.
My textbook states that;
'Sulfuric acid is a strong acid, however this is only true for one of the two hydrogen atoms. When H2SO4 dissolves in water, 1 H+ ion dissociates'
E.g. H2SO4 ---> H+ + HSO4-
'However, the HSO4- ion only partially dissociates, behaving like a weak acid'
E.g. HSO4- ------> (this should be a reversible sign but no such key exists) H+ + SO42-
How is this correct, because surely the H2SO4 is the weak acid as not all the H+ ions dissociate hence complete dissociation doesn't occur and the HSO4- is a strong acid as all the H+ ions available dissociate. Am I missing something?
Thanks to anyone that can help
Chemistry hard acids and bases a level Watch
- Thread Starter
- 06-01-2017 15:32
- 06-01-2017 18:31
The choice of the arrows shows that H2SO4 is a strong acid and it is a strong acid.
- 06-01-2017 19:58
H2SO4 is a strong acid, as it completely dissociates
H2SO4 -------> H+ + HSO4
What happens is that when 1 H+ ion is removed from the H2SO4 molecule, it is harder for the 2nd H+ ion to be removed. So therefore, HSO4 behaves like a weak acid as only some of the 2nd H+ ions are released (partially dissociates).