Answer:
According to libretexts the answer would be B. decreases.
Explanation:
If the hydrogen concentration increases, the pH decreases, causing the solution to become more acidic. This happens when an acid is introduced. ... If the hydrogen concentration decreases, the pH increases, resulting in a solution that is less acidic and more basic
17.8 mL NaOH
<em>Step 1.</em> Write the chemical equation
Fe^(2+) + 2NaOH → Fe(OH)2 + 2Na^(+)
<em>Step 2.</em> Calculate the moles of Fe^(2+)
Moles of Fe^(2+) = 500 mL Fe^(2+) × [0.0230 mmol Fe^(2+)]/[1 mL Fe^(2+)]
= 11.50 mmol Fe^(2+)
<em>Step 3.</em> Calculate the moles of NaOH
Moles of NaOH = 11.50 mmol Fe^(2+) × [2 mmol NaOH]/[1 mmol Fe^(2+)]
= 23.00 mmol NaOH
<em>Step 4.</em> Calculate the volume of NaOH
Volume of NaOH = 23.00 mmol NaOH × (1 mL NaOH/1.29 mmol NaOH)
= 17.8 mL NaOH
The concentration of diluted solution is 0.16 M
<u>Explanation:</u>
As, the number of moles of diluted solution and concentrated solution will be same.
So, the equation used to calculate concentration will be:

where,
are the molarity and volume of the concentrated HCl solution
are the molarity and volume of diluted HCl solution
We are given:

Putting values in above equation, we get:

Hence, the concentration of diluted solution is 0.16 M