F2 IS WS04 Answers

1st Term WS 04 Submission date：_____________ Name：______________________ Class & no.：2 _________(     )

7.2       Burning

A. What is burning?

i      Words to know:

	English term	Write the words again	Chinese term
1	React		發生反應
2	Fuel		燃料
3	Oxygen		氧

i      Fill in the blanks:

1        Burning is a chemical process化學過程 involving oxygen / fuel and fuel / oxygen.

2        When fuels burn in air, they react with oxygen and produce carbon dioxide and water.

light / heat energy and heat / light energy are given out.

3        carbon dioxide and water are produced when a wooden splint burns in air.

4        Write down the word equation文字方程式 of burning.

           fuel + oxygen ------> energy + carbon dioxide + water

i      Matching:

The substances involved in burning.	•Fuel	•	Carbon dioxide
	•Oxygen	•	Fuel
The substances produced in burning.	•Carbon dioxide	•	Heat
	•Water	•	Light
The energy produced in burning.	•Heat	•	Oxygen
	•Light	•	Water

i      Short questions:

1        What are involved in the process of burning?

Fuel and oxygen

2        What are produced in the process of burning?

Carbon dioxide and water

3        How can we test for the products of burning? Describe the test results.

Burn produces carbon dioxide and water. We can use hydrogencarbonate indicator to test for carbon dioxide. The colour changes from red and yellow. (Or we can use lime water to test for carbon dioxide. The colour changes from colourless and milky.)

Water can be tested by dry cobalt chloride paper. The colour changes from blue to pink.