Illustrated Guide to Home Chemistry Experiments

Chapter 20 Laboratory: Quantitative Analysis 363

FIGURE 20-1: Nearing the endpoint of the titration

TABLE 20-2: Quantitative analysis of chlorine bleach by redox titration—observed and calculated data

Item value

A. Mass of empty 100 mL volumetric flask __________. ____ g

B. Mass of volumetric flask + 100.0 mL of chlorine bleach __________. ____ g

C. Mass of chlorine bleach (B – A) __________. ____ g

D. Density of chlorine bleach (C/100) ______._____ g/mL

E. Volume of chlorine bleach sample ______._____ mL

F. Initial volume of sodium thiosulfate titrant ______._____ mL

G. Final volume of sodium thiosulfate titrant ______._____ mL

H. Volume of sodium thiosulfate titrant used (F – G) ______._____ mL

I. Moles of sodium thiosulfate required to reach endpoint ___.________ mol

J. Moles of sodium hypochlorite present in the sample (G/2) ___.________ mol

K. Mass of sodium hypochlorite present in the sample ______. ________ g

L. Mass of sample ______. ________ g

M. Mass percentage of sodium hypochlorite ______.______ %