In an experiment, as in the set-up above, two glass containers A and B of different sizes are joined together with a tube and clipped. Water is poured into container A to a height of 30 cm and a red liquid is poured into B to a height of 10 cm. The clip is then removed so that the liquids join together.

1. State two observations that will be made immediately the clip is removed. Explain the observations in (i) What two observations will be made after a long time? Explain.

2. State the observations that will be made about nails 1, 2, 3, and 4.

3. State the observations that will be made about the temperatures recorded by thermometers A, B, C, and D.

4. What mode of heat transfer is demonstrated in the experiment?

5. State one effect of heat that is associated with the experiment.

6. State the aim of the experiment.

The set-up below is used in the preparation of ammonia gas in the laboratory

Study it and answer the questions that follow

1. Name the parts labeled a, b and c.

2. What is the meaning of the arrow sign d?

3. What is the function of the calcium oxide?

4. Why has c been tilted downwards?

5. State the method by which the gas is collected.

6. How will you test for the gas?

7. Give the names and the chemical formulae of the compounds that form the content of c.

In an experiment, a leaf that is partly green and partly yellow is plucked from a tree and the leaf is
I. boiled for a minute
II. dipped in warm alcohol
III. washed in cold water
IV. dipped in iodine solution
One part of the leaf turns blue-black after the dipping in iodine solution while the other part remains unchanged.

1. Explain why each of the processes I, II and III is carried out.

2. Which part of the leaf turns blue-black? Explain.

3. Why does the other part of the leaf not change colour?

4. What conclusion can you draw from the experiment?