F2 IS 2nd Term QZ 07: 10.4 anwers

10.4

Word Translation (8 marks)

i    Write down the English terms of the following Chinese terms:

	Chinese term	English term
1	碳酸鈣	Calcium carbonate
2	腐蝕 (動詞)	Corrode
3	腐蝕 (名詞)	Corrosion
4	腐蝕性的	Corrosive
5	氫	Hydrogen
6	石灰石	Limestone
7	大理石	Marble
8	爆鳴聲	‘Pop’ sound

Fill in the Blanks (8 marks)

1        Some metals react with dilute acids and give out (1) hydrogen and heat. During the

reaction, the metals decrease in size, showing that acids have (2) corrosive effect on these metals.

2        The gas produced in the reaction between acid and some metals can be tested by a burning splint.

The gas burns with a (3) ‘pop’ sound.

3        We should not use acidic detergents to clean the surfaces of some building materials such as

(4) marble / limestone and (5) limestone / marlbe, because both of them contain

(6) calcium carbonate which is easily (7) corroded by acids.

The gas produced in the reaction is (8) carbon dioxide.

Multiple Choice (5 marks)

Circle the letter of the best answer for each question.

1.    When magnesium strip is added to dilute hydrochloric acid, gas bubbles are given out.

The gas can

A.   relight a glowing splint.

B.   turn hydrogencarbonate indicator yellow.

C.   give a ‘pop’ sound with a burning splint.

D.   turn lime water milky.

2.       Which of the following metals react(s) with dilute acids?

(I)   Zinc                                 (II)   Magnesium                              (III) Copper

A. (I) only              B. (I) and (II) only         C. (II) and (III) only       D. (I), (II) and (III)

3.       Which of the following metals reacts the most vigorously with dilute hydrochloric acid?

A.   Zinc                 B.    Magnesium            C.    Copper                    D.    Iron

  

4.       Which of the following is the gas given off when limestone pieces are added to dilute sulphuric acid?

A.   Hydrogen

B.   Oxygen

C.   Chlorine

D.   Carbon dioxide

5.       Which of the following building materials react(s) with dilute acids?

(I)   Marble                     (II)   Limestone                       (III) Iron

A. (I) only              B. (I) and (II) only          C. (II) and (III) only       D. (I), (II) and (III)

Challenging Questions (Bonus 2 marks)

1.      Explain why we should not use metal saucepans to cook “pork trotters in vinegar sauce”.

Vinegar contains acid (ethanoic acid) that may corrode the metal saucepans.