1
A sample of air that has been passed through caustic potash will
- A. contain more oxygen than nitrogen
- B. rekindle a glowing splint
- C. have no action on lime water
- D. contain no water vapour
- E. be free of noble gases
2
Chlorine is prepared on a large scale by the
- A. electrolysis of concentrated sodium chloride solution
- B. action of manganese (IV) oxide on hot concentrated hydrochloric acid
- C. action of concentrated tetraoxosulphate (IV) acid on sodium chloride
- D. oxidation of concentrated hydrochloric acid with potassium tetraxosulphate (VII)
- E. action of dilute mineral acids on bleaching powder
3
Which of the following oxides is amphoteric?
- A. Na2O
- B. Fe2O3
- C. AI2O3
- D. CaO
- E. CuO