Question

An aqueous solution has [C6H5COOH] = 0.110 M and [Ca(C6H5COO)2] = 0.200 M. Ka = 6.3 × 10-5 for C6H5COOH. The solution volume is 5.00 L. What is the pH of the solution after 10.00 mL of 5.00 M NaOH is added? Group of answer choices 4.81 4.86 4.75 4.70 4.65

Answer 1

4.86

Step-by-step explanation:

The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution.

Please kindly check attachment for the step by step solution of the given problem.

Answer 2

The answer is 4.8659

Step-by-step explanation:

Given:

[C₆H₅COOH]=0.11M

[C₆H₅COO]=2*0.2=0.4M

Ka=6.3x10⁻⁵

First, calculate the pKa:

`pKa=-logKa=-log(6.3x10^(-5) )=4.2007`

The pH is:

`pH=pKa+log(C6H5COO])/([C6H5COOH]) =4.2007+log(0.4)/(0.11) =4.7614`

Like the volume is 5L, the volume of C₆H₅COO is x, then, the volume of C₆H₅COOH is 5-x

`4.7614=4.2007+log(0.4x)/(0.11*(5-x))`

`0.5607=log(0.4x)/(0.11*(5-x))`

Solving for x:

x=2.49L=2490mL of C₆H₅COO

2510mL of C₆H₅COOH

The milimoles of C₆H₅COOH and C₆H₅COO is:

nC₆H₅COOH=(0.11*2510)-50=226.1mmol

nC₆H₅COO=(0.4*2490)+50=1046mmol

The pH is:

`pH=4.2007+log(1046)/(226.1) =4.8659`