Question

-e-laboratory Assignment Name: ead the experiment and answer the following questions as directed by your instructor A student is performing a titration. Diagrams of the buret at the beginning and the end of the titration are shown at right. To the correct number of significant figures, what is the initial volume, the final volume, and the volume of solution added during the titration? 16 2) Formic acid (HCOOH) is a weak acid with K. - 1.8 x 10-4. a) Write a reaction that shows the result when formic acid reacts with NaOH. b) If 10.0 mL of 0.10 M HCOOH is mixed with 5.0 mL of NaOH, what type of solution will exist? c) What will be the pH of the solution in question b? d) If you made a solution of sodium formate (NaHCOO), would you expect the pH to be below 7, above 7, or exactly 7.0? 3) A 10.00 mL sample of buffer with pH - 4.00 is titrated with both HCl and NaOH. a) If 16.57 mL of 0.175 M HCl is required to titrate the base in the buffer, what is (base) in the buffer? b) If 14.64 mL of 0.125 M NaOH is required to titrate the acid in the buffer, what is (acid in the buffer? c) What is pK, for this buffer?

Answer 1

1. We need three signif ad three significant figures to write the reading a burette measurement from 1 ml to 10 mland & four significant numbers over 10ml Now the fram of the burette at the begening, besining shows value tas between 6.6 ml and 6.7 ml . We significant members here. We have a diagram s an at and 6.7 ml . We had three and the tird one w division of buy diagram of burette a the tird one we have to estimate. The smallest sion of burette is o.1 ml hot from the ram of burette at the begining, the estimated svake is 4. Therefore the burette reading is 6.64m. from the digram at the right the estimated value is 2. Therefore the b S 21-32 ml, the significant a numbers are four. Therefore & initial rolume = 6.64 mL. Final volume = 21:32 mb. And volume of the solution added= (21:32-664) mL - 14.68 mL 2.a) for The reaction of formic acid with Noor Naon ŕ shown below - teooh & Naon HCOONa + H20 6) The nature of the solution will depend on the molar concentration of Naon Here it is only mentioned the volume of Naotsomtion 15 ml). Without molar conentration it is not possible to predict them nature of the solution