Question

PILDI student titrated 0.180 g of an unknown acid with 0.10 M NaOH solution and the data set was obtained: mL of 0.IM NaOH pH mL of 0.1M NaOH pH 2.20 20 3.25 22 28 4.00 4.25 4.50 4.81 5.25 5.55 5.75 6.10 6.32 6.70 7.00 9.00 11.20 11.70 12.00 12.22 12.40 12.60 30 32 14 16 36 38 1. Prepare a titration curve using Microsoft Excel. See Appendix C for directions on graphing. 2. Is this acid monoprotic or diprotic? Briefly explain. 3. Is this acid strong or weak? Briefly explain. 4. Determine the molar mass of the unknown acid. 5. Determine the pK (s) of the acid. 6. Identify the acid using the table on the previous page.

please help me answer questions 2 through 6

thanks

Answer 1

As from giren data, Equivalence point observed at pH greater than 7. Regarding to the fact, it is the titration af weak arid vs strong base. We have titrant NaOH (stsong base), So acid should be weath. so, by giren belon formula, it can be shows, acetic acid is the titrand , haring one equiralence point. pka z 4.75 as pH a 8.3 Acetic acid is monotropic Polar mass = 60 g/mol. Go answers, a. 2. monotropic 3. weak acid 4. molar mass : 60 g/mol 5. pka = 4.75 6. Acetic acid.