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. [1]   b forms a grey-green precipitate with aqueous ammonia. [1]   c forms a white precipitate with aqueous sodium hydroxide. [1]   d forms a cream precipitate with acidified aqueous silver nitrate. [1]   e forms a white precipitate with acidified aqueous barium nitrate. [1] 2.2   Describe how to do a flame test on a sample of a salt. [2] 2.3   Magnesium phosphate contains magnesium ions, Mg2+ , and phosphate ions, PO43- . Deduce the formula of magnesium phosphate. [1]       [8]  

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.    

1.29 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?

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

1.16 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?  

1.10 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

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?

1.20 Many metals are extracted from their ores by heating the metal oxide with carbon. Which metal cannot be extracted using this method?