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You'll find Sec 4.7, especially the part about titrations on pp 136- 138, to be helpful for this lab.
In the first part of the experiment, you are standardizing NaOH to be used in the second part of the lab. For each trial (titration of a known amount of primary standard KHP by the unknown NaOH), you need to calculate the NaOH concentration as follows:
Average your results and use the average NaOH concentration to do the acid analysis in part B.
Part B: Determination of the molecular weight of a solid acid
You will do three titrations here; calculate the molecular weight of the acid separately for each trial, and report the average of your weights.
At the equivalence point in the titration of the unknown acid by NaOH, we have
Since we know the concentration of the base (NaOH) from the standardization in part A, and since we know the volume of base delivered in each titration, we can calculate moles of base at the equivalence point:
Since moles acid = moles NaOH, we know how many moles of acid were in the sample.
To find the molar mass of the acid in the sample, we divide the sample mass (g) by the number of moles of acid:
Make this calculation for each trial and report the average molar mass of the acid.