Question 84
Zara and Sofia put 50 cm³ of alkali into a conical flask. They added a few drops of universal indicator to the alkali. They used a burette to add acid to the alkali. Zara added the acid 10 cm³ at a time. Sofia stirred the contents of the conical flask each time acid was added. They recorded the pH after each addition of acid.
The table shows their results.
| Volume of acid added in cm³ | 0 | 10 | 20 | 30 | 40 | 50 |
|---|---:|---:|---:|---:|---:|---:|
| pH of solution | 12 | 11 | 10 | 9 | 8 | 7 |
What colour was the alkali and universal indicator solution at the start?
The table shows their results.
| Volume of acid added in cm³ | 0 | 10 | 20 | 30 | 40 | 50 |
|---|---:|---:|---:|---:|---:|---:|
| pH of solution | 12 | 11 | 10 | 9 | 8 | 7 |
What colour was the alkali and universal indicator solution at the start?
