Question

When answering this problem, report the answer with the appropriate number of significant figures. When entering units, use proper abbreviated units with proper capitalization.A solution is prepared by pipetting 5.00 mL of 0.0098 molar HCl into a 100.0 mL graduated cylinder, and adding enough water to prepare 50.0 mL of solution. Calculate the pH of this solution.

Answer 1

Answer: pH of the solution is 3.3

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in L)}}$     .....(1)

Molarity of HCl solution = 0.0098 M

Volume of solution = 50.0 mL

Putting values in equation 1, we get:

$0.0098M=\frac{\text{Moles of HCl}\times 1000}{50.0ml}\\\\\text{Moles of HCl}=\frac{0.0098mol/L\times 50.0}{1000}=0.00049mol$

As 1 mole of HCl is giving 1 mole of $H^+$

0.00049 mole of HCl is giving =$\frac{1}{1}\times 0.00049=0.00049$ mole of $H^+$

pH =$-log[H^+]$

pH =$-log[0.00049]$

pH=3.3

Thus the pH od the solution is 3.3