Acid-base equilibria
Acid-base equilibria
define acid & base:
acid is a proton (H+) donor & base is a proton acceptor
Note: in order to accept a proton, a base has to contain a lone pair of
electrons to form a dative covalent bond with the proton
Q) what are amphoteric substances?
Substances like water, which can act as either acids or bases, are
amphoteric substances
for eg:
Conjugate acid-base pairs:
,remember: every acid has a conjugate base & every base has a
conjugate acid
Q) what are monoprotic & diprotic acids?
Monoprotic: acids that dissociates to form one mole of H+, per
mole of acid
eg: HCl, HNO3...
diprotic: acids that dissociate to form 2 moles of H+, per mole of acid
eg: H2SO4
Note: monoprotic/diprotic are also known as "monobasic"/"dibasic"
Q) Why sulfuric acid is a strong acid?
, H2SO4 is a strong acid while HSO4 is a weak acid; because Ka
for the 1st step of the dissociation is > than the Ka for the 2nd
step as most of the H+ ions are formed in 1st step
Remember: when 2 acids react with each other, the stronger acid [
the one with a higher Ka value] will act as an acid while the other acid
will behave as a base
for eg:
H2SO4 + HNO3 [reversible sign] [H2NO3]+ + HSO4-
Q) What are strong & weak acids?
Note: the stronger the acid, the greater the concentration of H+ ions
& therefore the lower the pH
Q) define pH:
Acid-base equilibria
define acid & base:
acid is a proton (H+) donor & base is a proton acceptor
Note: in order to accept a proton, a base has to contain a lone pair of
electrons to form a dative covalent bond with the proton
Q) what are amphoteric substances?
Substances like water, which can act as either acids or bases, are
amphoteric substances
for eg:
Conjugate acid-base pairs:
,remember: every acid has a conjugate base & every base has a
conjugate acid
Q) what are monoprotic & diprotic acids?
Monoprotic: acids that dissociates to form one mole of H+, per
mole of acid
eg: HCl, HNO3...
diprotic: acids that dissociate to form 2 moles of H+, per mole of acid
eg: H2SO4
Note: monoprotic/diprotic are also known as "monobasic"/"dibasic"
Q) Why sulfuric acid is a strong acid?
, H2SO4 is a strong acid while HSO4 is a weak acid; because Ka
for the 1st step of the dissociation is > than the Ka for the 2nd
step as most of the H+ ions are formed in 1st step
Remember: when 2 acids react with each other, the stronger acid [
the one with a higher Ka value] will act as an acid while the other acid
will behave as a base
for eg:
H2SO4 + HNO3 [reversible sign] [H2NO3]+ + HSO4-
Q) What are strong & weak acids?
Note: the stronger the acid, the greater the concentration of H+ ions
& therefore the lower the pH
Q) define pH:
