Hey this question stumped me.
I have to List the below with the strongest acid being 1 and the weakest acid being 4, i had a go with what i know just about the names, but the Ka values throw me.
Hydrofluoric acid - KHF = 3.5 x 10-4
Sulfuric acid - Kh2so4 = 1.2 x 10-2
Acetic acid - Kch3cooh = 1.8 x 10-5
Phosphoric acid- Kh3po4 = 7.5 x 10-3
Basically i went with Phos, Sulf, Hydro, Acetic. Strongest to weakest.
Any help appreciated thx.
When looking at their Ka's..
The smaller the number the weaker the acid.
suchas: 1.8 x 10-5
is a smaller number than 3.5 x 10-4
, which is smaller than 7.5 x 10-3
, which is smaller than 1.2 x 10-2
Thus the strongest to the weakest is:
Kh2so4 > Kh3po4 > KHF > Kch3cooh.
Does this help with understanding the Ka's ??
You can also guess acid strength by looking at the anions of the acids.
The more stable the cooresponding anion, the stronger the acid.