Experiment WS 3: 7.2A

Kowloon Tong School (Secondary Section)

F.2 Integrated Science

Experiment Worksheets 3

Name: _________________ (    )                                                               Date: __________________

Class: 2 _______

Experiment 7.2A: What is given out when a wooden splint burns? (P.16 - 17)

Objective: To study what is given out in burning.

Procedures:

1. Put a burning splint into a gas jar filled with oxygen. 2. When the burning splint goes out, take it out and immediately立即 cover the gas jar completely with the glass plate. 3. Touch接觸 the outside of the gas jar with your hand.   (a) What do you feel? My hand feels warm
4. (a) Observe the inner wall of the gas jar. What do you see on the inner wall of the gas jar? A layer of mist  (b) Let a piece of dry cobalt chloride paper touch the inner wall of the gas jar. Take it out immediately and cover the gas jar with the glass plate completely.      (i) What happens to the cobalt chloride paper? _______________________________________.
5.   Add 5 cm3 of hydrogencarbonate indicator into the gas jar. Cover the gas jar with the glass plate immediately. Shake the gas jar gently. Observe the colour of the indicator.    (a) What happens to the indicator?       It changes from red to yellow

Conclusion結論:

Ø   From the result of 3(a), it shows that heat energy is given out during burning

Ø   From the result of 4(a)(b), it shows that water vapour is given out during burning.

Ø   From the result of 5(a), it shows that carbon dioxide is given out during burning.