In an experiment, a sample of an oxide of lead was heated over coke for some time. The following results were obtained:
Mass of the oxide before heating = 8.92g
Mass of residue after heating = 8.28g

a) Determine the empirical formula of the oxide of lead (Pb = 207, O = 16) (2 Marks)

b) Write an equation for the reaction in the experiment above (1 Mark)

A fixed mass of a gas occupies 200cm³ at 0°C and 740mmHg pressure. Calculate its volume at − 48°C and 780mmHg. (3 Marks)

Element Q reacts with dilute acids, but not with cold water. Element R does not react with dilute acids. Element S displaces element P from its oxide. P reacts with cold water. Arrange the four elements in order of reactivity, starting with the most reactive element. (2 Marks)

The setup below was used to investigate the reaction of a certain gas with lead (II) nitrate solution

a) Identify gas A     (1 Mark)

b) State the observation made in the trough containing lead (II) nitrate solution (1 Mark)

c) Write an ionic equation for the reaction occurring in the trough (1 Mark)

What mass of magnesium carbonate would remain if 15.0g of magnesium carbonate reacts with 25cm³ of 4M hydrochloric acid solution? (3 Marks)

Name the catalyst used in the following processes:

a) Large scale manufacture of ammonia gas in the Haber process (1 Mark)

b) Large scale manufacture of concentrated sulphuric (VI) acid in the Contact process (1 Mark)

c) Laboratory preparation of oxygen using hydrogen peroxide (1 Mark)

Nitric (V) acid may be prepared in the laboratory by the action of concentrated sulphuric (VI) acid in a suitable nitrate and distilling off the nitric (V) acid
                             

a) Why does the setup only consist of apparatus made of glass? (1 Mark)

b) Pure nitric (V) acid is colourless but the product in the collection vessel is yellow. Explain (1 Mark)

c) Why is it possible to separate nitric (V) acid from sulphuric (VI) acid in the setup? (1 Mark)

a) Group VIII elements are said to be inert. Explain. (1 Mark)

b) In terms of structure and bonding, explain why group VIII elements exist as gases at room temperature (2 Marks)

The sketch graph below shows the relationship between pressure and temperature of a gas in a fixed volume container.
                                                        

a) State the relationship between pressure and temperature that can be deduced from the graph (1 Mark)

b) Using the kinetic theory of matter, explain the relationship shown by the sketch graph (2 Marks)

Briefly describe how sodium carbonate powder can be obtained in the laboratory starting with concentrated sodium hydroxide solution (2 Marks)