In: Chemistry
For each strong acid solutions, determine [H3O+],[OH−], and pH.
1) 0.24M HCl
2)2.5x10^-2 M HNO3
3) A solution that is 7.5x10^-2 M in HBr and 2.2x10^-2 M in HNO3
1)
[H+] = [HCl] = 0.24 m
use:
[OH-] = Kw/[H+]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[OH-] = (1.0*10^-14)/[H+]
[OH-] = (1.0*10^-14)/(0.24)
[OH-] = 4.167*10^-14 M
use:
pH = -log [H+]
= -log (0.24)
= 0.6198
use:
pOH = -log [OH-]
= -log (4.167*10^-14)
= 13.3802
[H3O+] = 0.24
[OH-] = 4.17*10^-14
pH = 0.620
2)
[H+] = [HNO3] = 2.5*10^-2 M
use:
[OH-] = Kw/[H+]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[OH-] = (1.0*10^-14)/[H+]
[OH-] = (1.0*10^-14)/(2.5*10^-2)
[OH-] = 4*10^-13 M
use:
pH = -log [H+]
= -log (2.5*10^-2)
= 1.6021
use:
pOH = -log [OH-]
= -log (4*10^-13)
= 12.3979
[H3O+] = 2.5*10^-2
[OH-] = 4.0*10^-13
pH = 1.60
3)
[H+] = [HBr] + [HNO3]
= 7.5*10^-2 M + 2.2*10^-2 M
= 9.7*10^-2 M
use:
[OH-] = Kw/[H+]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[OH-] = (1.0*10^-14)/[H+]
[OH-] = (1.0*10^-14)/(9.7*10^-2)
[OH-] = 1.031*10^-13 M
use:
pH = -log [H+]
= -log (9.7*10^-2)
= 1.0132
use:
pOH = -log [OH-]
= -log (1.031*10^-13)
= 12.9868
[H3O+] = 9.7*10^-2
[OH-] = 1.03*10^-13
pH = 1.013