Question

QUESTION 1: What is the pH of an aqueous solution with a hydrogen ion concentration of [H ] = 5.6 × 10–5 M?

QUESTION 2: Complete this table pf values for thre aqueous solutions at 25C.


[H]+ [OH-] ph
Solution A 7.7*10^-6 M X X
Solution B X 0.097 X
Solution C X X 8.84

Answer 1

QUESTION 1:

Given that; [H ] = 5.6 × 10–5 M

We know that Ph z = - log [H+]

= - log 5.6 × 10–5

= - (-4.25)

=4.25
QUESTION 2:

Solution A:

Given that; [H ] = 7.7 × 10–6 M

We know that Ph z = - log [H+]

= - log 7.7 × 10–6

= - (- 5.11 )

= 5.11

We know that [ H+] [OH-]= 1.0*10^-14

Then [OH-]= 1.0*10^-14/[ H+]

= 1.0*10^-14/7.7 × 10–6

= 1.3*10^-9

Solution B X 0.097 X

Given that [OH-] = 0.097

We know that [ H+] [OH-]= 1.0*10^-14

Then [H+]= 1.0*10^-14/[ OH-]

= 1.0*10^-14/0.097

= 1.03*10^-13

[H ] = 1.03*10^-13 M

We know that Ph = - log [H+]

= - log 1.03*10^-13

= - (- 12.99)

= 12.99

Solution C X X 8.84

We know that [H+] =10^-Ph

= 10^-8.84

= 1.45*10^-9 M

We know that [ H+] [OH-]= 1.0*10^-14

Then [OH-]= 1.0*10^-14/[ H+]

= 1.0*10^-14/1.45*10^-9

= 6.9*10^-6