Question

Calculate the pH expected for the 0.0100 M HCl solution used in part A.

Intermediate value Final value 1a. Calculate the pH expected for the 0.0100 M HCl solution used in part A. 1b. Calculate the percent error between the expected pH and your measured pH of the 0.0100 M HCI. our To ☺ QUESTION 2 Intermediate value Final value 2a. Calculate the pH of 0.100 M CH3COOH (approximation method). Kg = 1.8 x 10-5 2b. Calculate the percent error between the calculated and your measured pHs of 0.100 M CH3COOH. calculated and your o ® QUESTION 3 Intermediate value Final value 3a. PK, of the acid chosen in part D 3b. Use the Henderson Hasselbach equation, the appropriate pka, and your measured pH of the phosphate buffer (part D), calculate the [base]/[acid) ratio. 3c. Nominal acid/base ratio. (Use the nominal concentrations and the volumes as instructed in the experiment writeup.) 3d. % error in the [base]/[acid) ratio
I'm so lost please help

Answer 1

ANSWER:

You have a 0.0100 M HCl solution. The HCl is a strong acid with the following chemical equation for the dissociation of the acid in water:

$HCl\, (aq)\rightarrow H^{+}\, (aq)+Cl^{-}\, (aq)$

Strong acids have a complete dissociation, this means that HCl is transformed completely into Cl^- and H⁺. Then, 1 mol of HCl produces 1 mol of H⁺. Thus, in a solution of HCl:

$[HCl]=[H^{+}]=0.0100 \, M$

Then, for the solution of 0.0100 M HCl, the concentration of H⁺ would be 0.0100 M, and the expected pH for this solution is

$pH=-log[H^{+}]=-log\left ( 0.0100 \right )$

$\mathbf{pH=2.00}$

The percent error between expected pH and measured pH is calculated with this equation:

$\%\, error=\frac{\left | pH_{measured}-pH_{expected} \right |}{pH_{expected}}\times 100\, \%$

$\%\, error=\frac{\left | 2.00-2.00 \right |}{2.00}\times 100\, \%$

$\mathbf{\%\, error=0.00\, \%}$