F2 IS QZ 03 anwers

Marks: =       /17 =    %

1st Term QZ 03 Submission date：_____________ Name：______________________ Class & no.：2 _________(     )

7.1AB

Word Translation (6 marks)

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

	Chinese term	English term
1	燃燒中的木條	Burning splint
2	帶星火的木條	Glowing splint
3	碳酸氫鹽指示劑	Hydrogencarbonate indicator
4	石灰水	Lime water
5	氯化鈷試紙	Cobalt chloride paper
6	未呼吸的空氣	Unbreathed air

Fill in the Blanks (11 marks)

1      We use glowing splint to test for oxygen that it will relight in oxygen.

2      We can use lime water to test for carbon dioxide. Its colour changes from colourless to milky.

We can also use hydrogencarbonate indicator to test for it. Its colour changes from red to yellow in carbon dioxide.

3      When we breathe on dry cobalt chloride paper, it turns from blue to pink.

4      Compared with breathed air, unbreathed air contains more oxygen but less carbon dioxide / water vapour / heat.

Challenging Questions (Bonus 2 marks)

Describe how you can identify breathed air and unbreathed air?

We can put burning splints into breathed air and unbreathed air respectively and measure the burning time (1). The burning splint in the unbreathed air should have a longer burning time (1).

OR

We can test both of them by hydrogencarbonate indicator. Breathed air can turn the indicator yellow but unbreathed air cannot.