Answer:
Explanation:
Given parameters:
pH of HNO₃ = 3.75
Unknown:
[OH⁻], concentration of hydroxyl ions = ?
pOH of the solution = ?
Solution
The pH or pOH scale is a convenient way of expressing the level of acidity or alkalinity of aqueous solutions.
The pH of a solution is the negative logarithm to base 10 of the hydrogen ion concentration of the solution:
pH = -log₁₀[H⁺]
pOH = -log₁₀[OH⁻]
For any aqueous solution, the sum of the pH and pOH is 14. That is;
pH + pOH = 14
Now solving for [OH⁻]:
HNO₃ + H₂O → H₃O⁺ + NO₃⁻
Since pH + pOH = 14
pOH = 14 - pH = 14 -3.75 = 10.25
since pOH = -log₁₀[OH⁻]
10.25 = -log₁₀(OH⁻)
[OH⁻] = inverse log₁₀(-pOH)
[OH⁻] = inverse log₁₀(-10.25) = 5.62 x 10⁻¹¹moldm⁻³
Answer:
5.62×10⁻¹¹ M
Explanation:
Given the pH of the nitric acid, ([tex]HNO_3[/tex])
pH = 3.75
Also, pH + pOH = 14
So, pOH = 14 - 3.75 = 10.25
pOH is the negative logarithm of the hydroxide ion concentration.
Thus,
pOH = -log[OH⁻ ]
So,
10.25 = -log[OH⁻ ]
[OH⁻ ] = Antilog (-10.25) = 5.62×10⁻¹¹ M
