1991 年

Which of the following tests should be used to detect the presence of sulphite ions in a given solution X ?

Which of the following graphs represents what would be obtained in a thermometric titration of 2M hydrochloric acid with potassium hydroxide solution?

Sulphur dioxide is passed into a test tube containing potassium dichromate solution acidified with dilute sulphuric acid. The colour of the solution gradually changes from orange to green. Which of the following statements concerning the above experiment is correct ?

What volume of water should be added to 100 cm³ of 2M hydrochloric acid to change the acid concentration to 0.2M?

When concentrated sulphuric acid is added to hydrated copper(II) sulphate crystals, which of the following would be observed ?

22 g calcium carbonate are allowed to react with 200 cm³ of 0.5 M hydrochloric acid until no further reaction occurs. What is the mass of calcium carbonate left behind? (Relative atomic masses: C = 12.0, O = 16.0, Ca = 40.0)

What is the number of moles of Fe³⁺ ions in 0.1 dm³ of 0.5M Fe₂(SO₄)₃ solution?

Iron(II) sulphate solution is mixed with chlorine water. Excess aqueous ammonia is then added to the mixture. What is the colour of the precipitate formed?

Propene reacts with acidified potassium permanganate solution to form

1.55 g of a hydrated sodium carbonate, Na₂CO₃ • xH₂O, react completely with 25 cm³ of 1 M hydrochloric acid. What is the value of x? (Relative atomic masses: H = 1.0, C = 12.0, O = 16.0, Na = 23.0)