Answer:
pH = 1.3
Explanation:
Since we are given a hydronium(H+) concentration and we know the volume, when adding water, we can find the final concentration through dilution. From there, you just need to take -log(H+) in order to get the pH.
Solving:
[tex]\text{Dilution Concentration} = \frac{\text{Total volume of solution after dilution}}{\text{Number of moles of } H^+}[/tex]
[tex]\text{Concentration after dilution} = \frac{0.1 \, \text{M} \times 0.5 \, \text{L}}{1 \, \text{L}} = \boxed{0.05 \, \text{M}}[/tex]
[tex]\text{pH} = -\log{[\text{H}^+]}\\\\\text{pH} = -\log{(0.05)} \approx -\log{(5 \times 10^{-2})} = -(-1.3) = \boxed{1.3}[/tex]
Therefore, the pH after 500mL of water is added is 1.3.
