Question

What is the hydronium ion concentration in a solution of HCl that has a pH of 4.65? × 10n M n = What is the hydroxide ion concentration in a solution of NH3 with a pOH of 4.65? × 10n M n =

Answer 1

These are two questions and two answers:

1) What is the hydronium ion concentration in a solution of HCl that has a pH of 4.65?

i) Data:

pH = 4.65
[H₃O⁺] = ?

ii) Formula: pH = - log [H₃O⁺]

iii) Calculations:

4.65 = - log [H₃O⁺] ⇒ [H₃O⁺] =


`[H_3O^+]=10^(-4.65)=2.24.10^(-5)`

2) What is the hydroxide ion concentration in a solution of NH3 with a pOH of 4.65?

i) Data:

pOH = 4.65
[OH⁻] = ?

ii) Formula: pOH = - log [OH⁻]

iii) Calculations:

4.65 = - log [OH⁻] ⇒ [OH] =


`[OH^-]=10^(-4.65)=2.24.10^(-5)`

Answer 2

q1)
pH scale is used to determine how acidic a solution is
pH can be calculated as follows
pH = - log[H₃O⁺]
when the pH has been given , the hydronium ion concentration can be determined
[H₃O⁺] = antilog(-pH)
[H₃O⁺] = antilog(-4.65)
[H₃O⁺] = 2.24 x 10⁻⁵ M
[H₃O⁺] is 2.24 x 10⁻⁵ M

q2)
pOH scale is used to determine the alkalinity of a solution. pOH can be calculated using the OH⁻ ion concentration
pOH = -log[OH⁻]
OH⁻ ion concentration can be calculated knowing the pOH value
[OH⁻] = antilog(-pOH)
[OH⁻] = antilog(-4.65)
[OH⁻] = 2.24 x 10⁻⁵ M
the answer is 2.24 x 10⁻⁵ M