The table shows the hydrogen ion concentration at four pH values. Use .
| pH | Hydrogen ion concentration / mol dm-3 |
|---|---|
| 3 | 1 × 10-3 |
| 4 | |
| 5 | 1 × 10-5 |
| 7 |
Complete the table by giving the hydrogen ion concentration at pH 4 and at pH 7.
[2]
State how the hydrogen ion concentration changes for each decrease of one pH unit.
[1]
The pH of a cell falls from 7 to 4. Calculate how many times greater the hydrogen ion concentration becomes.
[2]