Form 4 Paper 2 Term 1 2019 Chemistry Exam Set 25 [PDF]

The diagram below shows the process of manufacturing sodium carbonate using ammonia soda process. Study it and answer the questions that follow.

1. Name gases A and B
   • A
   • B
2. Name liquid C and solid D
   • C
   • D
3. Write equations of the reactions in:
   • Tower P
   • Tower R
4. Name the product T formed at chamber R and give one of its uses.

The set-up below was used to prepare and collect gas X. During the experiment cleaned magnesium ribbon was strongly heated before heating the wet glass wool.

1. Name gas X
2. Why is magnesium ribbon cleaned before it is used?
3. State one observation that would be noted in the reaction tube.
4. Write the equation for the reaction in the reaction tube.
5. State one industrial use of the solid product formed in the reaction tube.
6. What precaution should be taken at the end of experiment? Explain.
7. At the end of the experiment 96.0cm³ of gas X were collected at 10°C and 1 atmosphere pressure. (Mg = 24, M.G.V = 22.4, T =0°C at stp, P = 1 atmosphere at sip).
   (i) Determine the volume gas X would occupy at s.t.p?
   (ii) Calculate the mass of magnesium ribbon used Mg = 24

Air was passed through several reagents as shown in the flow chart below.

1. Name the major components of air.
2. Write an equation for the reaction which takes place in the chamber with:
   1. Concentrated sodium hydroxide
   2. Excess heated copper turnings
   3. Excess heated magnesium powder
3. Name one gas which escapes from the chamber containing magnesium powder. Give a reason for your answer.
4. Name the substance that was eliminated by electrostatic precipitation.
5. Name a reagent that can be used in place of concentrated sodium hydroxide.
6. Name substance C
7. State three uses of gas C.

Study the information below and answer the questions that follow

1. Aluminium chloride AlCl₃ has an unexpected bond type and structure.
   1. State the type of bond and the structure in AlCl₃.
      Bond type
      Structure
   2. What type of bonding would AlCI₃ be expected to have why?
   3. Why is the melting point of AlCI₃ not indicated in the table above?
2. A piece of blue litmus paper is placed in a solution of sodium chloride and a solution of aluminium chloride. Explain what would be observed in each case.
   Sodium chloride solution
   Aluminium chloride solution
3. Explain the large difference in the melting point of the compound of formula MgO and P₄O₁₀.
4. Write down the equations for the reaction between the compounds of formula Na₂O and water.
5. Silicon(IV) chloride gets hydrolyzed by water Write a balanced equation for this reaction.

A compound Z has a molar mass of 56g and contains 853% carbon and 14.3% hydrogen by mass.
(C = 12, H = 1)

1. 1. Determine the molecular formula of compound Z.
   2. Give the structural formula of the sixth member of the homologous series to which Z belongs.
2. Compound Z reacts with a few drops of acidified potassium chromate (VII) solution
   
   1. State the observation made during the reaction.
   2. Name the organic product formed in the reaction on (c) above.
3. Z reacted with liquid bromine in the dark (room conditions).
   
   1. State the observation made during the reaction
   2. Write the equation for above.
   3. Name the organic product formed in (d) above.
   4. State the type of reaction in (d) above.