Final answer:
To find the concentration of an unknown acid solution, perform a titration by slowly adding a known concentration of NaOH. Measure the volume of NaOH added and use the formula to calculate the concentration of the acid solution. In this case, the unknown acid solution has a concentration of 0.0158 M.
Step-by-step explanation:
The student's question is about the concentration of an unknown acid solution. To find the concentration, the student performs a titration by slowly adding a known concentration of NaOH to the acid solution until a color change occurs. By measuring the volume of NaOH added, the student can calculate the concentration of the acid solution. In this case, the initial volume of NaOH is 12.6 mL and the final volume is 28.9 mL.
The concentration of the unknown acid solution can be calculated using the formula:
concentration of unknown acid solution = (volume of NaOH added) * (concentration of NaOH) / volume of acid solution
Substituting the given values:
concentration of unknown acid solution = (28.9 mL - 12.6 mL) * (0.055 M) / 50.0 mL = 0.0158 M