Chapter 4, Problem 139SCQ

Two students titrate different samples of the same solution of HCl using 0.100 M NaOH solution and phenolphthalein indicator (Figure 4.12). The first student pipets 20.0 mL of the HCl solution into a flask, adds 20 mL of distilled water and a few drops of phenolphthalein solution, and titrates until a lasting pink color appears. The second student pipets 20.0 mL of the HCl solution into a flask, adds 60 mL of distilled water and a few drops of phenolphthalein solution, and titrates to the first lasting pink color. Each student correctly calculates the molarity of an HCl solution. What will the second student’s result be?

1. (a) four times less than the first student’s result
2. (b) four times greater than the first student’s result
3. (c) two times less than the first student’s result
4. (d) two times greater than the first student’s result
5. (e) the same as the first student’s result