A student investigates the change in electrical conductivity as dilute lead(II) nitrate solution is added to dilute potassium bromide solution.
This is the student’s method.
Step 1add 50 cm3 of potassium bromide solution to a beaker
Step 2 measure the electrical conductivity of the solution
Step 3add 10 cm3 of lead(II) nitrate solution to the beaker
Step 4 stir the mixture
Step 5 measure the electrical conductivity of the mixture
Repeat steps 3, 4 and 5 until a total of 50 cm3 of lead(II) nitrate solution has been added.
The table shows the student’s results.
| Total volume of lead(II) nitrate solution added in cm3 | Electrical conductivity in arbitrary units |
| 0 | 10.00 |
| 10 | 9.80 |
| 20 | 9.77 |
| 30 | 9.40 |
| 40 | 9.20 |
| 50 | 9.00 |