化學 1994 年 DSE、CE 選擇題（第 3 頁）

21.

Which of the following label(s) should be placed on a bottle containing tetrachloromethane?

22.

Which of the following statements concerning 25.0 cm³ of 0.1 M hydrochloric acid and 25.0 cm³ of 0.1 M ethanoic acid is/are correct?

(1)They contain the same number of hydrogen ions.

(2)They require the same volume of 0.1 M sodium hydroxide solution for complete neutralization.

(3)They react with excess zinc granules at the same rate.

23.

Which of the following reagents can be used to distinguish between sodium sulphite solution and sodium sulphate solution ?

(1)barium chloride solution

(2)acidified potassium permanganate solution

(3)potassium iodide solution

24.

X, Y and Z are three different elements. The electronic diagram (showing electrons in the outermost shells only) of the compound formed by X, Y and Z is shown below:

Which of the following statements are correct ?

(1)There is one electron in the outermost shell of an atom of X.

(2)There are five electrons in the outermost shell of an atom of Y.

(3)There are eight electrons in the outermost shell of an atom of Z.

25.

Concentrated sulphuric acid turns blue litmus paper red and then black. On the basis of these colour changes, which of the following deductions concerning concentrated sulphuric acid are correct ?

(1)It contains H⁺(aq) ions.

(2)It is an oxidizing agent.

(3)It is a dehydrating agent.

26.

A compound has the following structure:

Which of the following statements about this compound are correct?

(1)It can decolourize bromine water.

(2)It can be polymerized.

(3)It can burn in air.

27.

Which of the following substances can be fermented to give an alcoholic drink ?

(1)grapes

(2)wheat

(3)potatoes

28.

Which of the following statements concerning a catalyst are correct?

(1)It can change the rate of a reaction.

(2)It can change the amount of product formed in a reaction.

(3)It remains chemically unchanged at the end of a reaction.

29.

Which of the following methods can be used to distinguish between solid sodium carbonate and calcium carbonate ?

(1)Heating the solid and testing the gaseous product with lime water.

(2)Testing the solubility of the solid in water.

(3)Conducting a flame test on the solid.

30.

For each of the following questions, decide whether each of the two statements is true or false. If both are true, decide whether the second correctly explains the first.

A.Both statements are true and the 2nd statement is a correct explanation of the 1st statement.

B.Both statements are true but the 2nd statement is NOT a correct explanation of the 1st statement.

C.The 1st statement is false but the 2nd statement is true.

D.Both statements are false.

1st statement	2nd statement
Hydrogen chloride has a lower melting point than sodium chloride.	In each molecule of hydrogen chloride, a hydrogen and a chlorine atom are joined together by a covalent bond.