化學 2010 年 DSE、CE 選擇題（第 5 頁）

41.

The structure of a detergent is shown below : CH₃(CH₂)₁₅COO⁻ Na⁺ Which of the following statements concerning this detergent is correct ?

42.

Which of the following hazard warning labels should be displayed on a bottle of concentrated hydrochloric acid ?

43.

Solution Y is added dropwise to a solution of NaOH containing several drops of phenolphthalein. The mixture suddenly changes from pink to colourless. Which of the following substances may Y be ?

(1)HCl(aq)

(2)KCl(aq)

(3)Cl₂(aq)

44.

In an experiment, 10 g of zinc granules is added to 100 cm³ of 1 M HCl(aq) in a beaker. Which of the following changes to the experiment can increase the initial rate of the reaction ?

(1)Use 200 cm³ of 1 M HCl(aq) to replace 100 cm³ of 1 M HCl(aq).

(2)Use 50 cm³ of 2 M HCl(aq) to replace 100 cm³ of 1 M HCl(aq).

(3)10 g of zinc granules of greater size are used instead.

45.

Which of the following reactions is / are neutralisation ?

(1)Cu + 4 HNO₃ → Cu(NO₃)₂ + 2 H₂O + 2 NO₂

(2)2 CH₃COOH + MgO → (CH₃COO)₂Mg + H₂O

(3)CH₃COOH + CH₃CH₂OH ⇌ CH₃COOCH₂CH₃ + H₂O

46.

At room temperature and pressure, 1 mole of gas A and 2 moles of gas B react completely to form 1 mole of gas C and 1 mole of gas D. If the temperature and pressure remain unchanged, which of the following will decrease after the reaction ?

(1)the mass of the gaseous mixture

(2)the volume of the gaseous mixture

(3)the total number of atoms making up the gases in the gaseous mixture

47.

Which of the following reagents can convert iron(II) ions to iron(III) ions ?

(1)chlorine water

(2)dilute nitric acid

(3)potassium bromide solution

48.

Which of the following experiments would give a colour change ?

(1)Sulphur dioxide is passed into a test tube containing bromine water.

(2)Sulphur dioxide is passed into a gas jar containing moist red flower petals.

(3)Sulphur dioxide is passed into a conical flask containing potassium iodide solution.

49.

For Questions 49–50, 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 are true and the second correctly explains the first.

B.Both are true but the second does not correctly explain the first.

C.The first is false but the second is true.

D.Both are false.

1st statement	2nd statement
When using a zinc-carbon cell in electrolysis, the carbon electrode of the cell is connected to the cathode of the electrolytic cell.	In a circuit using zinc-carbon cell to supply electricity, electrons in the external circuit flow to the carbon electrode of the zinc-carbon cell.

50.

For Questions 49–50, 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 are true and the second correctly explains the first.

B.Both are true but the second does not correctly explain the first.

C.The first is false but the second is true.

D.Both are false.

1st statement	2nd statement
The reaction of charcoal with oxygen is endothermic.	Charcoal that is placed in fire can be ignited.