Final answer:
To find the concentration of HCl in the titration, use the mole ratio and set up an equation. Solve the equation to find the concentration.
Step-by-step explanation:
To determine the concentration of the HCl solution, we can use the equation:
NaOH + HCl → NaCl + H2O
The balanced equation tells us that the mole ratio of NaOH to HCl is 1:1. So, since 25 mL of 0.2 M NaOH neutralizes 20 mL of HCl, we can set up the following equation:
(0.2 M NaOH) x (25 mL) = (x M HCl) x (20 mL)
By solving this equation, we find that the concentration of the HCl is 0.25 M. Therefore, the correct answer is option b. 0.25 M.