Look at Figure 5.1 which shows solutions taken in test tubes A,B,C and D. What colour is expected when a piece of red litmus paper is dropped in each test tube? Nature of the solutions is given in the table for your help.

| Test Tube | Nature of solution | Change in colour of red litmus |
| A | Natural | |
| B | Basic | |
| C | Acidic | |
| D | Natural |
| Test Tube | Nature of solution | Change in colour of red litmus |
| A | Natural |
No change |
| B | Basic |
Turn blue |
| C | Acidic |
No change |
| D | Natural |
No change |