QUESTION 3 3.1   Chlorine exists as a number of different isotopes. What is meant by the term isotopes? 3.2   A chloride ion has a symbol shown.   Right-click on the button to open the data booklet in a new tab.            a How many neutrons are contained in this chloride ion?   b How is a chloride ion formed from the chlorine atom?   c Which atom forms an ion with a 1+ charge and has the same number of electrons as Cl-?        

1.27 An isotope of chromium has an atomic mass of 52g.mol-1 . Which statement about an atom of this isotope of chromium is correct?

1.28 During the electrolysis of concentrated hydrochloric acid, gases are produced at both electrodes. Which statement describes the test result for the gas collected at the negative electrode?

1.19 Which statement about aluminium is not correct?

1.14 Three gas jars contain carbon dioxide, hydrogen, and oxygen. Which one of the following tests could be used to discover which gas is in each jar?

1.39 Which physical property is used to separate the nitrogen and oxygen from air?

1.11 The diagram shows the reaction between zinc oxide and dilute hydrochloric acid.   Right-click on the button to open the data booklet in a new tab.        Which terms describe the reaction?   Endothermic Neutralization A Yes Yes B Yes No C No Yes D No No

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?

1.3 Element Y has 10 protons. Element Z has 11 protons. Which statement is correct?

  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.   4.2 Sulphur dioxide is a toxic gas.     State one environmental reason why sulphur dioxide should not be released into the atmosphere. 4.3 Describe the test for sulphur dioxide. test … observations …