pH of strong Acids/Bases

[ulbasour]

In relation to the definition of a strong acid or base,
Is a strong Acid classified as having a pH <1 and a strong base >13? or when we look at pH curves, do we just assume that when the curve is high its a strong Base and low it is a strong acid, even thought the pH at these points may not be <1 or >13?

[cltf]

only 3 Strong acids, HCl, H2SO4 and HNO3. pH is based on concentration at 25 degrees. Theoretically Ethanoic acid can have a pH of 1 if the concentration was enough. Same theory for bases.

[ulbasour]

only 3 Strong acids, HCl, H2SO4 and HNO3. pH is based on concentration at 25 degrees. Theoretically Ethanoic acid can have a pH of 1 if the concentration was enough. Same theory for bases.

But if you get a qusn with a titration curve and the intial pH is 2 and it goes to 12, even though it has a sharp endpoint, and it asks you to identify what type of acid/bases are involved, would you say strong acid-base or weak acid-base?

[luken93]

Usually,
Strong A = 1~3
Weak A = 4~6
Weak B = 8~11
Strong B = 12~14

It'll be pretty obvious, they aren't gonna put it in the middle of the acid range and make you guess which side it's on

[Mao]

Usually,
Strong A = 1~3
Weak A = 4~6
Weak B = 8~11
Strong B = 12~14

It'll be pretty obvious, they aren't gonna put it in the middle of the acid range and make you guess which side it's on

Not quite. Strength of acids and bases depends on their molecular properties. Strong acids can exist at high pH as very dilute solutions (e.g. 0.00001M HCl).

For the purpose of VCE, strong acids are HCl, H2SO4, HNO3. Weak acids are the acids that are listed in your data booklet.