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  QUESTION 4 4.1 Sulphur dioxide reacts with aqueous sodium sulphite to produce a compound with the following composition by mass: 29.1% Na, 40.5% S and 30.4% O. Calculate the empirical formula of this compound.   [3] 4.2 Sulphur dioxide is a toxic gas.     State one environmental reason why sulphur dioxide should not be released into the atmosphere. [1] 4.3 Describe the test for sulphur dioxide. test … observations …   [2]       [6]

1.5 The table contains information about four substances.     Melting point in degree Celsius Electrical conductivity     When molten In aqueous solution A 13 No Yes B 99 Yes Yes C 790 Yes Yes D 1500 No insoluble   Which substance is Potassium Chloride?

1.25 A student is asked to measure the time taken for 0.4 g of magnesium carbonate to react completely with 25.0 cm3 of dilute hydrochloric acid. Which pieces of apparatus does the student need?

1.8 The diagram shows an unsuccessful experiment to nickel plate a pan.    What change is necessary to nickel plate the pan?   Right-click on the button to open the data booklet in a new tab.    

1.18 Five elements have proton numbers 10, 12, 14, 16 and 18. What are the proton numbers of the three elements that form oxides?

1.29 Which statements about endothermic reactions are correct?   1 The energy of the products is greater than the energy of the reactants. 2 The energy of the reactants is greater than the energy of the products. 3 The temperature of the surroundings increases during the reaction. 4 The temperature of the surroundings decreases during the reaction.

1.36 Which pair of elements reacts together most violently?

1.16 Elements X, Y and Z are in Group 7 of the Periodic Table.   X is a gas. Y is less reactive than Z. Z is a red liquid. When X, Y and Z are put in order of increasing proton number, which order is correct?  

1.15 The diagram shows an outline of part of the Periodic Table.   Right-click on the button to open the data booklet in a new tab.        Which statement about elements X, Y and Z is not correct?

1.10 The diagram shows that two gases are formed when concentrated hydrochloric acid is electrolysed using inert electrodes.   Right-click on the button to open the data booklet in a new tab.        Which row correctly describes the colours of the gases at the electrodes?   anode (+ve) cathode (–ve) A colourless colourless B colourless yellow-green C yellow-green colourless D yellow-green yellow-green