Strong-Acid, Strong Base Titration Questions?

[匿名]

2016-10-18 4:43 am

1. 20.00 mL of 0.200 M HBr is titrated with 0.200 M KOH.

First determine the concentration of H+ in this solution. _____ M

Then, determine the pH of the solution, based on the H+ concentration. _____

2. What is the pH of the solution when 19.90 mL of KOH has been added? (Use an ice table if needed).

I appreciate your help! Thank you!!

回答 (1)

不用客氣

2016-10-18 8:42 am

✔ 最佳答案

1.
20.00 mL of 0.200 M HBr is titrated with 0.200 M KOH.
First determine the concentration of H+ in this solution. __0.200__ M
Then, determine the pH of the solution, based on the H+ concentration. __0.7__

Calculations :
No. of moles of HBr in 1 L of solution = 0.200 mol

1 mole of HBr contains 1 mole of H⁺.
Hence, no. of moles of H⁺ in 1 L of solution = 0.200 mol
The concentration of H⁺ in this solution = 0.200 M

pH = -log[H⁺] = -log(0.200) = 0.7

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2
What is the pH of the solution when 19.90 mL of KOH has been added?

There is insufficient information for calculation because the concentration of KOH is unknown.

Assume that the concentration of KOH = M mol/L

No. of moles of KOH = (M mol/L) × (19.90/1000 L) = 0.01990M mol
pOH = -log[OH⁻] = -log(0.01990M)
H = 14.0 - pOH = 14.0 - {-log(0.01990M)} = 14.0 + log(0.01990M)

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