Final answer:
To find the concentration of hydrochloric acid, the student performed a titration using a known sodium hydroxide solution. The concentration can be calculated using the titration formula C1V1 = C2V2, rearranged to solve for the unknown concentration of the acid, where C1 is the target concentration and V1 is the volume of the acid used.
Step-by-step explanation:
To determine the concentration of the unknown hydrochloric acid solution, the student used the titration method. The titration involves adding a known concentration of titrant to a solution until the reaction reaches the endpoint, which is indicated by a color change due to the phenolphthalein indicator. The key to finding the concentration of the original solution is to use the titration formula:
C1V1 = C2V2
Where C1 is the concentration of the original hydrochloric acid solution, V1 is the volume of the hydrochloric acid solution used in titration, C2 is the concentration of the sodium hydroxide titrant, and V2 is the volume of the titrant used to reach the endpoint. In this case:
The concentration of the original hydrochloric acid solution (C1) can be calculated by rearranging the formula and solving for C1:
C1 = (C2V2) / V1
Substituting the known values and solving for C1 gives us the concentration of the hydrochloric acid solution.
It's important to convert all volumes to the same unit (Liters) before performing the calculation if the volumes are not already given in the same unit.