Get premium membership and access questions with answers, video lessons as well as revision papers.

Form 3 Chemistry Chlorine and Its Compounds Questions and Answers

Form 3 Chemistry: Chlorine and its compounds topical questions and answers. All answers are in video format.

Lessons (38)

• 1.    (a) In an experiment hydrogen chloride gas was prepared and reacted with aluminium turnings to form a solid Q and gas R as shown below. (i) Name: Liquid P Solid Q Gas R (ii) Name another substance that could serve the same purpose as the concentrated sulphuric (VI) acid. (iii) Explain the following observation. When a blue litmus paper was dipped into the water in the beaker at the end of the
  10m 54s

• 2.    In an experiment, chlorine gas was passed into moist hydrogen sulphide in a boiling tube as shown in the diagram. (a) What observation was made in the boiling tube? (b) Write an equation for the reaction which took place in the tube. (c) What precaution should be taken in carrying out this experiment? Give reason.
  3m 1s

• 3.    The information below relates to elements L, Q, R and T. the letters do not represent the actual symbols of the elements. Arrange the elements in order of their increasing reactivity.
  3m 13s

• 4.    (a) In an experiment, dry hydrogen chloride gas was passed through heated zinc turnings as shown in the diagram below. (i) What is the function of water in the flask? (ii) Write equations for the reactions that took place in the tubes S and V. (iii) How would the total mass of the tube V and its contents compare before and after the experiment?Explain. (b) Chlorine can be prepared by using the
  15m 25s

• 5.    The equation below represents a redox reaction. #2FeCl_2(aq) + Cl_2(g) to 2FeCl_3(aq)#. Identify the reducing agent. Give a reason
  0m 59s

• 6.    What is the oxidation number of chlorine in #CIO^(-)4#
  1m 10s

• 7.    The diagram below shows a set up for the laboratory preparation and collection of dry chlorine gas. (a) Name: (i) Substance G (ii) A suitable drying agent (b) What property of chlorine makes it possible for it to be collected as shown in the diagram?
  3m 46s

• 8.    The equation below represents a redox reaction. #Mg(s) + 2HCI(aq) to MgCI_2(aq) +H_2(g)# (a) Write down the equation for the reduction process. (b) Which substance is oxidized?
  1m 44s

• 9.    (a) Give the name of reagent which when reacted with concentrated hydrochloric acid produce chlorine gas. (b) A student set out to prepare iron (III) chloride using the apparatus shown in the diagram below. (i) Explain why: (I) It is necessary to pass chlorine gas through the apparatus before heating begins. (II) Calcium oxide would be preferred to calcium chloride in the guard tube.
  11m 31s

• 10.    The following two tests were carried out on chlorine water contained in two testtubes: (a) A piece of blue flower was dropped into the first test-tube. Explain why the flower ached. (b) The second test-tube was corked and exposed to sunlight. After a few days, it was found to contain a gas that rekindled a glowing splint. Write an equation for the reaction which produced the gas.
  2m 51s

• 11.    The set up below was used to prepare hydrogen chloride gas and react it with iron powder. Study it and answer the questions that follow. At the end of the reaction, the iron powder turned into a light green solid. (a) Identify the light green solid. (b) At the beginning of the experiment, the pH of the solution in container L was about 14. At the end, the pH was found to be 2. Explain.
  2m 40s

• 12.    When excess chlorine gas was bubbled into hot concentrated sodium hydroxide, the following reaction occurred. #3CI_2(g) + 6NaOH(aq) to NaCIO_3(aq) + 5NaCI_2(aq) +3H_2O(l)#. In which product did chlorine undergo oxidation?
  1m 19s

• 13.    (a) The table below shows some properties of chlorine, bromine and iodine. Complete the table by giving the missing information in (i), (ii) and (iii). (b) Chlorine gas is prepared by reacting concentrated hydrochloric acid with manganese (IV) oxide. (i) Write the equation for the reaction between concentrated hydrochloric acid and manganese (IV) oxide. (ii) What is the role of manganese (IV)
  10m 27s

• 14.    Calcium oxide can be used to dry ammonia gas. (a) Explain why calcium oxide is not used to dry hydrogen gas? (b) Name one drying agent for hydrogen chloride gas.
  1m 40s

• 15.    The reaction between hot concentrated sodium hydroxide and chlorine produces sodium chlorate (V), sodium chloride and water. (a) Write the equation for the reaction (b) Give one use of sodium chlorate (V).
  2m 27s

• 16.    Name the process which takes place when: (a) Solid carbon (IV) oxide (dry ice) changes directly into gas (b) A red litmus paper turns white when dropped into chlorine water. (c) Propene gas molecules are converted into a giant molecules
  1m 34s

• 17.    The diagram below represents the set up that was used to prepare and collect hydrogen chloride gas in the laboratory. (a) State the purpose of concentrated sulphuric (VI) acid in the wash bottle. (b) Write an equation for the reaction between dry hydrogen chloride gas and heated iron. (c) Hydrogen chloride gas is dissolved in water to make hydrochloric acid.State one use of hydrochloric acid.
  3m 43s

• 18.    State and explain the observation made when excess ammonia gas reacts with chlorine gas.
  1m 37s

• 19.    Complete the following table by filling in the missing test and observations.
  3m 24s

• 20.    In an experiment, a test tube full of chlorine water was inverted in chlorine water as shown in the diagram below and the set up left in sunlight for one day. After one day, a gas was found to have collected in the test tube (a) Identify the gas (b) What will happen to the PH of the solution in the beaker after one day? Give an explanation.
  3m 2s

• 21.    The diagram below is part of a set up used in the laboratory preparation of a gas. Complete the diagram to show how a dry sample of the gas can be collected.
  2m 21s

• 22.    (a) Two reagents that can be used to prepare chlorine gas are manganese (IV) oxide and concentrated hydrochloric acid. (i) Write an equation for the reaction (ii) Give the formula of another reagent that can be reacted with concentrated hydrochloric acid to produce chlorine gas. (iii) Describe how chlorine gas could be dried in the laboratory. (b) In an experiment, dry chlorine gas was reacted
  11m 31s

• 23.    The diagram below represents a set up for large scale manufacture of hydrochloric acid. study it and answer questions that follow. (a) Name substance X (b) What is the purpose of the glass beads? (c) Give two uses of hydrochloric acid.
  2m 36s

• 24.    During a class experiment, chlorine gas was bubbled into a solution of potassium iodide (a) State the observation made (b) Using an ionic equation, explain why the reaction is redox.
  3m 31s

• 25.    Under certain conditions, chlorine gas reacts with sodium hydroxide to form sodium hypochlorite. (a) Name the condition under which sodium hydroxide reacts with chlorine to form sodium hypochlorite. (b) State two uses of sodium hypochlorite.
  1m 2s

• 26.    (a) State and explain what would happen if a dry litmus paper was dropped in gas jar of chlorine. (b) By using only dilute hydrochloric acid, describe how a student would distinguish between barium sulphite from barium sulphate.
  2m 6s

• 27.    (a) The diagram below is part of a set up used to prepare and collect dry chlorine gas. (i) Complete the diagram to show how a dry sample of chlorine gas can be collected (ii) Name another substance and condition that can be used instead of manganese(IV) oxide. (iii) Write an equation for each of the following I. chlorine gas reacting with iron II. chlorine gas reacting with hot concentrated
  11m 19s

• 28.    State and explain what would happen if a dry red litmus paper was dropped in a gas jar of dry chlorine.
  0m 27s

• 29.    A gas jar full of chlorine water was inverted over water and allowed to stand for some time. (a) State and explain two observations made in the gas jar after some time. (b) Write the equation for the reaction between chlorine and hot concentrated potassium hydroxide.
  2m 9s

• 30.    (a) The set-up below was used to prepare dry hydrogen chloride gas, and investigate its effect on heated iron filings. (i) Name substance L (ii) Name liquid M. (iii)What will be observed in tube B (iv) Write an equation for the reaction that occurs in tube B. (v) Why is the gas from tube B burnt? (b) (i) Explain the following observations: (I) a white precipitate is formed when hydrogen chloride
  3m 52s

• 31.    Hydrogen chloride gas can be prepared by reacting sodium chloride with an acid. (a) Write an equation for the reaction between sodium chloride and the acid. (b) Give two chemical properties of hydrogen chloride gas. (c) State two uses of hydrogen chloride.
  1m 45s

• 32.    The diagram below represents the set up that was used to prepare and collect hydrogen chloride gas in the laboratory. (a) State the purpose of concentrated sulphuric acid in the wash bottle. (b) Write an equation for the reaction between dry hydrogen chloride gas and heated iron.
  1m 32s

• 33.    During an experiment, chlorine gas was bubbled into a solution of potassium iodide. (a) State the observations made. (b) Using an ionic equation, explain why the reaction is redox.
  1m 37s

• 34.    Explain the observation made when chlorine gas is passed through a solution of potassium iodide.
  0m 31s

• 35.    (a) What is meant by the term bleaching? (b) Write the formula of the bleaching agent formed when chlorine gas reacts with aqueous sodium hydroxide. (c) State the role of chlorine in water treatment.
  0m 37s

• 36.    Figure 3 shows a set-up used by a student to prepare dry chlorine gas in the laboratory. Identify three mistakes in the set-up, and give a reason for each.
  1m 33s

• 37.    (a) The diagram in Figure 4 was used to prepare hydrogen chloride gas which was passed over heated iron powder. (i) Give a pair of reagents that will produce hydrogen chloride gas in flask A. (ii) Name the substance in flask B. (iii) State the observation made in the combustion tube. (iv) Write an equation for the reaction in the combustion tube. (iv) Describe a chemical test for hydrogen
  3m 47s

• 38.    A boiling tube filled with chlorine was inverted in a trough containing the same solution and the set-up left in sunlight for about 2 hours. (a) State the observation made in the boiling tube (b) Explain the observation made in (a) (c) Write an equation for the reaction that occurred in the boiling tube
  1m 16s