1. What type of substance is found in indigestion tablets?

a) A strong alkali
b) A strong acid
c) A salt
d) A base

2. Which of the following statements about bases are true?

a) They dissolve in water to form a solution which contains an excess of hydrogen ions (H⁺)
b) They turn universal indicator red
c) They neutralise acids
d) They are all soluble in water

3. Which of the following is not a base?

a) Non-metal oxides
b) Metal oxides
c) Metal carbonates
d) Metal hydroxides

4. Some bases will dissolve in water to form solutions which contain an excess of ions.

5. Most bases are in water but some will dissolve to form solutions, that is solutions which contain an excess of hydroxide ions (OH^-) .

6. Which of the following is a common characteristic of alkalis?

a) They are slippery and soapy to the touch
b) They have a pH below 7
c) Some will turn universal indicator yellow
d) They will neutralise alkalis

7. What is the pH range for alkalis?

a) 0-6
b) 7
c) 7-12
d) greater than 7

8. Ammonium hydroxide solution can be described as?

a) A weak alkali
b) A strong alkali
c) A weak acid
d) Neither acidic or basic as it is insoluble

9. The alkali sodium is formed when the base sodium oxide dissolves in water.

10. Which one of the following bases is soluble in water?

a) Copper oxide
b) Sodium hydroxide
c) Calcium carbonate
d) Iron (II) oxide