Chemistry hard acids and bases a level

Watch
IGCSETANK
Badges: 11
Rep:
?
#1
Report Thread starter 4 years ago
#1
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
0
reply
Hajra Momoniat
Badges: 16
Rep:
?
#2
Report 4 years ago
#2
The choice of the arrows shows that H2SO4 is a strong acid and it is a strong acid.
0
reply
Vish24xy
Badges: 0
Rep:
?
#3
Report 4 years ago
#3
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).
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Poll: What factors affect your mental health most right now? Post-lockdown edition

Anxiousness about restrictions easing (30)
5.32%
Uncertainty around my education (65)
11.52%
Uncertainty around my future career prospects (66)
11.7%
Lack of purpose or motivation (75)
13.3%
Lack of support system (eg. teachers, counsellors, delays in care) (32)
5.67%
Impact lockdown had on physical health (28)
4.96%
Social worries (incl. loneliness/making friends) (60)
10.64%
Financial worries (35)
6.21%
Concern about myself or my loves ones getting/having been ill (22)
3.9%
Exposure to negative news/social media (34)
6.03%
Difficulty accessing real life entertainment (15)
2.66%
Lack of confidence in making big life decisions (56)
9.93%
Worry about missed opportunities during the pandemic (46)
8.16%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise