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CHEMISTRY FORM 1

  1. Explain why most of the laboratory apparatus are made of glass.                              (2marks)

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  • Explain how a mixture of sand and common salt be separated                    (3 marks)

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Name the apparatus named:

A………………………………………………………………………………   D…………………………………………………………………………………   E………………………………………………………………………………… B)  Name the liquids         C…………………………………………………………           B……………………………………………………………    
  C B A D E  

The diagram below shows a set up of separating water from ethanol. Study it and answer the following questions

C) Name any other two methods that can be used to separate immiscible liquids                              (2 marks)

1.……………………………………………………………………………  2. ……………………………………………………………………………………

  1. Classify the processes below as either physical change or chemical change   (4 marks)
  2. Burning candle wax……………………………………………………………….
  3. Dissolving sugar in hot water………………………………………………
  4. Rusting of iron……………………………………………………………………
  5. Burning candle wick………………………………………………………………….
  • A) State two conditions necessary for rusting                             (2 marks)

        1. ………………………………………………………………..

        2…………………………………………………………………………

       B) State any three methods used to prevent rusting.                               (3 marks)

1. ………………………………………………………………………………. 2. ………………………………………………………………………

3. …………………………………………………………………………….

  • Dilute hydrochloric acid was added in a solid R in a test tube. The gas evolved put off a burning splint with a pop sound.
  • Name the gas that was evolved……………………………………………………….                         (1 mark)
  • State any two possible examples of solid R                                                                          (2 marks)

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  • Name any two commercial indicators                                                                                     (2 marks)
  • ………………………………………………………………… 2. …………………………………………………………………….
  • Liquids A, B, C, D and E were tested and found to have pH values of 10, 2, 7.0, 5 and 13 respectively.  Of the above solutions, which solution was likely to be;                    

                                                                                                                                                                 (5 marks)

  1. Sodium hydroxide………………………………………………
  2. Lemon juice………………………………………………………….
  3. Distilled water………………………………………………………
  4. Hydrochloric acid…………………………………………………
  5. Ammonium solution……………………………………………
  • A student set up apparatus as shown below. The candle was lit and left to burn for some time

                                                                       Gas jar

                                                             500cm3                                                                                    

  1. Explain the observations that were made at the end of the experiment        (2 marks)
  • Calculate the percentage of air that was used up during the experiment given that the final volume of air in the gas jar was 400 cm3 (2 marks)
  • Explain the causes of deviation of the percentage above from the theoretical values. (2 marks)
  • Give any 3 observations that would be made if wet iron was used sprinkled on the gas jar instead of the candle         ( 3 marks)

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  • The diagram below was used to prepare a certain gas X. study it and answer the questions that follow.
  1. Name gas X                                                        (1 mark)
  • State any 3 properties of gas X.                 (3 marks)
  • Name any other method that can be used to prepare gas X.
  • COMPLETE THE FOLLOWING WORD EQUATIONS
  1. Carbon + oxygen 
  • Sodium + oxygen
  • Arrange the following elements in order of decreasing reactivity                               (3 marks)

                Sodium, magnesium, potassium, gold, lead silver