Final answer:
To calculate the pH of a solution containing formic acid and sodium formate, we can use the Henderson-Hasselbalch equation. The pH of the solution is 4.05.
Step-by-step explanation:
To calculate the pH of a solution containing formic acid and sodium formate, we can use the Henderson-Hasselbalch equation:
pH = pKa + log(base/acid)
In this case, formic acid is the acid and sodium formate is its conjugate base. The pKa of formic acid is 3.75. The concentration of formic acid is 0.1 M and the concentration of sodium formate is 0.2 M. Plugging these values into the formula, we get:
pH = 3.75 + log(0.2/0.1) = 3.75 + log(2) = 3.75 + 0.301 = 4.05
Therefore, the pH of the solution is 4.05.