Question

Complete the table for each of the following solutions. Omit molarity units from your answers. [H] POH [OH) 0.0070 M HNO; 2.5 M NaOH Submit Show Hints

Answer 1

1) for row 1:

[H+] = [HNO3] = 0.0070 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)/(7*10^-3)

[OH-] = 1.429*10^-12 M

use:

pH = -log [H+]

= -log (7*10^-3)

= 2.1549

use:

pOH = -log [OH-]

= -log (1.429*10^-12)

= 11.8451

Answers:

[H+] = 7.0*10^-3

pH = 2.15

pOH = 11.85

[OH-] = 1.4*10^-12

2) for row 2:

[OH-] = [NaOH] = 2.5 M

use:

[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)/2.5

[H+] = 4*10^-15 M

use:

pH = -log [H+]

= -log (4*10^-15)

= 14.3979

use:

pOH = -log [OH-]

= -log (2.5)

= -0.3979

Answers:

[H+] = 4.0*10^-15

pH = 14.40

pOH = -0.398

[OH-] = 2.5