1. An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?

2. Two aqueous solutions P and Q have pH of 5 and 13 respectively. The correct inference is that:

3. The pH of a solution is 7. How can you increase its pH?

4. Sodium carbonate is a basic salt because it is a salt of

5. Which gas is evolved when acids react with metals?

6. A sample of soil is mixed with water and allowed to settle. The clear supernatant solution turns the pH paper yellowish-orange. Which of the following would change the colour of this pH paper to greenish- blue?

7. Which of the following gives the correct increasing order of acidic strength?

8. If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done?

9. Farmers neutralise the effect of acidity of the soil by adding

10. A teacher gave two test tubes to the students, one containing water and the other containing sodium hydroxide. She asked them to identify the test tube containing sodium hydroxide solution. Which one of the following can be used for the identification?