In: Chemistry
For each of the following strong base solutions, determine [OH−],[H3O+], pH, and pOH.
1. 6.77×10−3 M LiOH,
2. 0.0412 M Ba(OH)2
3. 5.9×10−4 M KOH
4. 3.0×10−4 M Ca(OH)2
1)
[OH-] = 6.77*10^-3 M
we have below equation to be used:
[H+] = Kw/[OH-]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[H+] = (1.0*10^-14)/[OH-]
[H+] = (1.0*10^-14)/0.00677
[H+] = 1.477*10^-12 M
we have below equation to be used:
pH = -log [H+]
= -log (1.477*10^-12)
= 11.83
we have below equation to be used:
pOH = -log [OH-]
= -log (6.77*10^-3)
= 2.17
[H3O+] = 1.477*10^-12 M
[OH-] = 6.77*10^-3 M
pH = 11.83
pOH = 2.17
2)
[OH-] = 2*[Ba(OH)2] = 2*0.0412 M = 8.24*10^-2
we have below equation to be used:
[H+] = Kw/[OH-]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[H+] = (1.0*10^-14)/[OH-]
[H+] = (1.0*10^-14)/0.0824
[H+] = 1.214*10^-13 M
we have below equation to be used:
pH = -log [H+]
= -log (1.214*10^-13)
= 12.9159
we have below equation to be used:
pOH = -log [OH-]
= -log (8.24*10^-2)
= 1.0841
[H3O+] = 1.214*10^-13
[OH-] = 8.24*10^-2
pH = 12.92
pOH = 1.08
3)
[OH-] = 5.9*10^-4
we have below equation to be used:
[H+] = Kw/[OH-]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[H+] = (1.0*10^-14)/[OH-]
[H+] = (1.0*10^-14)/5.9*10^-4
[H+] = 1.695*10^-11 M
we have below equation to be used:
pH = -log [H+]
= -log (1.695*10^-11)
= 10.7709
we have below equation to be used:
pOH = -log [OH-]
= -log (5.9*10^-4)
= 3.2291
[H3O+] = 1.695*10^-11
[OH-] = 5.9*10^-4
pH = 10.77
pOH = 3.23
4)
[OH-] = 2*[Ca(OH)2]= 2* 3.0*10^-4 = 6*10^-4
we have below equation to be used:
[H+] = Kw/[OH-]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[H+] = (1.0*10^-14)/[OH-]
[H+] = (1.0*10^-14)/6.0*10^-4
[H+] = 1.667*10^-11 M
we have below equation to be used:
pH = -log [H+]
= -log (1.667*10^-11)
= 10.7782
we have below equation to be used:
pOH = -log [OH-]
= -log (6*10^-4)
= 3.2218
[H3O+] = 1.667*10^-11
[OH-] = 6*10^-4
pH = 10.78
pOH = 3.22