You are given a solution of HCOOH (formic acid) with an approximate concentration of 0.20 M and you will titrate this with a 0.1105 M NaOH. If you add 20.00 mL of HCOOH to the beaker before titrating, approximately what volume of NaOH will be required to reach the equivalence point?

• A. 40.00 mL
• B. 18.00 mL
• C. 36.20 mL
• D. 22.00 mL

Answer: (C)

Verified step by step guidance

1. Start by understanding that at the equivalence point in a titration, the moles of acid will equal the moles of base. Here, formic acid (HCOOH) is being titrated with sodium hydroxide (NaOH).
2. Calculate the moles of HCOOH initially present in the solution. Use the formula: \( \text{moles} = \text{concentration} \times \text{volume} \). The concentration of HCOOH is 0.20 M and the volume is 20.00 mL (convert this to liters by dividing by 1000).
3. Next, determine the moles of NaOH required to reach the equivalence point. Since the reaction between HCOOH and NaOH is a 1:1 stoichiometry, the moles of NaOH needed will be equal to the moles of HCOOH calculated in the previous step.
4. Use the concentration of NaOH (0.1105 M) to find the volume of NaOH needed. Rearrange the formula \( \text{moles} = \text{concentration} \times \text{volume} \) to solve for volume: \( \text{volume} = \frac{\text{moles}}{\text{concentration}} \).
5. Convert the volume of NaOH from liters to milliliters by multiplying by 1000, as the final answer should be in milliliters.