- The set up below was used to prepare dry hydrogen chloride gas, and investigate its effect on heated iron fillings.
- Name substance L. (1 mark)
- Name liquid M. (1 mark)
- What will be observed in tube B? (1 mark)
- Write an equation for the reaction that occurs in tube B. (1 mark)
- Why is the gas from tube B burnt? (1 mark)
- Explain the following observations:
- A white precipitate formed when hydrogen chloride gas is passed through aqueous silver nitrate. (1 mark)
- Hydrogen chloride gas fumes in ammonia gas. (1 mark)
- State two uses of hydrogen chloride gas. (1 mark)
- Explain the following observations:
- The diagram below is a representation of an industrial process for the manufacture of a bleaching powder.
- Name substance Q. (1 mark)
- When the bleaching powder is added to water during washing, a lot of soap is used. Explain. (1 mark)
- The set up below was used to prepare dry hydrogen chloride gas, and investigate its effect on heated iron fillings.
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- The grid below represents part of the periodic table. Study it and answer the questions that follow. The letters are not the actual symbols of the elements.
- Select the most reactive metal. Explain. (2 marks)
- Select the element that can form an ion with a charge of 3-. (1 mark)
- Select an alkaline earth metal. (1 mark)
- Which group I element has the highest first ionization energy? Explain. (2 marks)
- Element A combines with chlorine to form a chloride of A. State the most likely pH value of a solution of the chloride of A. Explain. (2 marks)
- Explain why molten calcium chloride and magnesium chloride conduct electricity while carbon tetrachloride and silicon tetrachloride do not. (2 marks)
- Under the same conditions, gaseous neon was found to diffuse faster than gaseous fluorine. Explain the observation. (F= 19.0: Ne= 20.0) (2 marks)
- The grid below represents part of the periodic table. Study it and answer the questions that follow. The letters are not the actual symbols of the elements.
- Draw the structures of the following:
- Butan-1-ol (1 mark)
- Hexanoic acid. (1 mark)
- Study the flow chart below and answer the questions that follow.
- State the conditions necessary for fermentation of glucose to take place. (1 mark)
- State one reagent that can be used to carry out process S. (1 mark)
- Identify gases: (2 marks)
P…………
T………… - How is sodium hydroxide kept dry during the reaction? (1 mark)
- Give one commercial use of process R. (1 mark)
- When one mole of ethanol is completely burnt in air, 1370 KJ of heat energy is released. Given that 1 litre of ethanol is 780 g, calculate the amount of heat energy released when 1 litre of ethanol is completely burnt. (3 marks)
(C = 12.0; H = 1.0; O = 16.0) - State two uses of ethanol other than an alcoholic drink. (2 marks)
- Draw the structures of the following:
- Other than temperature, state two factors that determine the rate of chemical reaction. (1 mark)
- A solution of hydrogen peroxide was allowed to decompose and the oxygen given off collected. After 5 minutes, substance G was added to the solution of hydrogen peroxide. The total volume of oxygen evolved was plotted against time as shown in the graph below
- Describe the procedure of determining the rate of reaction at minute 12. (3 marks)
- How does the production of oxygen in region AB compare to that in region BC? (2 marks)
- Write an equation to show the decomposition of hydrogen chloride. (1 mark)
- Sulphur (IV) oxide reacts with oxygen to form Sulphur (VI) oxide as shown in the equation below:
- Explain the effect of the yield SO3 of lowering the temperature for this reaction. (2 marks)
- Name one catalyst used for the reaction. (1 mark)
- Other than temperature, state two factors that determine the rate of chemical reaction. (1 mark)
- The scheme below shows some of the reactions of solution D. Study it and answer the questions that follow.
- Give a possible cation present in solution D. (1 mark)
- Write an ionic equation for the reaction in step II. (1 mark)
- What observations would be made in step V? Give a reason. (2 marks)
- Explain why the total volume of hydrogen gas produced in step I was found to be very low although calcium and solution D were in excess. (2 marks)
- State one use of substance E. (1 mark)
- Starting with sodium chloride, describe how a pure sample of lead (II) chloride can be prepared in the laboratory. (3 marks)
- State a property of anhydrous calcium chloride which makes it suitable for use as a drying agent for chlorine gas. (1 mark)
- Name another substance that can be used to dry chlorine gas. (1 mark)
- The scheme below shows some of the reactions of solution D. Study it and answer the questions that follow.
- The diagram below represents a set up of an electrolytic cell that can be used in the production of aluminium.
- On the diagram, label the anode. (1 mark)
- Write an equation for the reaction at the anode. (1 mark)
- Give a reason why the electrolytic process is not carried out below 9500C. (1 mark)
- Give a reason why the production of aluminium is not carried out using reduction process? (1 mark)
- Give two reasons why the aluminium ions are discharged. (2 marks)
- State two properties of duralumin that make it suitable for aircraft industry. (2 marks)
- Name two environmental effects caused by extraction of aluminium. (2 marks)
- On the diagram, label the anode. (1 mark)
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- Dissolving of potassium nitrate in water is an endothermic process. Explain the effect of increase in temperature on the solubility of potassium nitrate. (2 marks)
- The table below shows the solubilities of potassium sulphate and potassium chlorate (V) at different temperatures.
- Draw the solubility curves for both salts on the same axis. (Temperature on the X- axis) (3 marks)
- A solution of potassium sulphate contains 20g of the salt dissolved in 100g of water at 1000C. This solution is allowed to cool to 250C.
- At what time will the crystals first appear? (1 mark)
- What mass of crystals will be present at 250C? (1 mark)
- Which of the two salts is more soluble at 300C? (1 mark)
- Determine the concentration of potassium nitrate in moles per litre when the solubility of the two salts is the same. (K = 39.0; O = 16.0; S =32.0)
- 100g of water at 1000C contains 19g of potassium chlorate (V). Describe how a solid sample of potassium sulphate at 600C can be obtained. (2 marks)
- Draw the solubility curves for both salts on the same axis. (Temperature on the X- axis) (3 marks)
- Dissolving of potassium nitrate in water is an endothermic process. Explain the effect of increase in temperature on the solubility of potassium nitrate. (2 marks)