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

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?

  QUESTION 2     This question is about ions and ionic compounds.   2.1   Choose from the following list of ions to answer the questions.   Br-          Ca2+            Cl –           Cr 3+           Cu 2+ K +                Li +               Na+                 SO32-           SO42-     Each ion may be used once, more than once or not at all. State which ion:     a gives a lilac colour in a flame test.   b forms a grey-green precipitate with aqueous ammonia.   c forms a white precipitate with aqueous sodium hydroxide.   d forms a cream precipitate with acidified aqueous silver nitrate.   e forms a white precipitate with acidified aqueous barium nitrate. 2.2   Describe how to do a flame test on a sample of a salt. 2.3   Magnesium phosphate contains magnesium ions, Mg2+ , and phosphate ions, PO43- . Deduce the formula of magnesium phosphate.        

  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 …        

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?

1.29 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.

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

1.8 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.    

1.36 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?