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(i) Soapy detergent.
(ii) Sodium chloride
(iii) To solidify the cleansing agent hence separate it from the alcohol
(iv) Potassium hydroxide.
(v) - It is cheap
- Biodegradable
johnmulu answered the question on May 25, 2017 at 06:47
- Study the scheme given above and answer the questions that follow. (Solved)
Study the scheme given above and answer the questions that follow.
(i) Name the reagents used in:
Step I.... Step II.. Step IV ...
(ii) Explain one disadvantage of the continued use of items made from the compound formed in step III.
Date posted: May 25, 2017. Answers (1)
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The structure shown below represent two cleansing agents, A and B.
Which cleansing agent would be more suitable for washing in water containing magnesium sulphate? Give a reason.
Date posted: May 25, 2017. Answers (1)
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Study the table below and answer the questions that follow:
(i) Which of the compounds is a solid at 10.0 o C? Explain.
(ii) Choose two compounds which are members of the same homologous series and explain the difference in their melting points.
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Date posted: May 25, 2017. Answers (1)
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A mixture of pentane and pentanoic acid was shaken with 0.1 M sodium hydroxide solution and let to separate as shown in the diagram below:
Name the main component in layer W.
Give a reason for the answer.
Date posted: May 25, 2017. Answers (1)
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A compound whose structure is shown below is found in a detergent
With reference to the structure, explain how the detergent removes grease during washing
Date posted: May 19, 2017. Answers (1)
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The diagram below represents a set-up of an electrolytic cell that can be used in the production of aluminium.
(a) Give a reason why the electrolytic process is not carried out below 950oC.
(b) Give a reason why the production of aluminium is not carried out using reduction process.
Date posted: May 19, 2017. Answers (1)
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The flow chart below shows some process involved in the industrial extraction of zinc metal.
(a) Name one ore from which zinc is extracted.
(b) Write the equation of the reaction taking place in unit II.
(c) Name two uses of zinc metal.
Date posted: May 19, 2017. Answers (1)
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The diagram below shows a simplified furnace used in the extraction of zinc. Study it and answer the questions that follow;
(i) Name two other substances that are also introduced in the furnace together with roasted ore.
(ii) In which physical state is zinc at point Y in the furnace? Give a reason.
(iii) Suggest a value for the temperature at point X in the furnance. Give a reason
Date posted: May 19, 2017. Answers (1)
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Iron is obtained from haematite using a blast furnance shown in figure 5 below.
(a)Four raw material are required for the production of iron. Three of these are iron oxide hot air and Limestone. Give the name of the fourth raw material.
(b) Explain why temperature in the region marked Y is higher than that of the incoming hot air.
Date posted: May 17, 2017. Answers (1)
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During the extraction of aluminium from its ores, the ore is first purified to obtain alumina. The flow chart below shows the stages in the extraction of aluminium from alumina.
(a) Name
(i) Substance C1
(ii) Process D1
(b) Give two reasons why aluminium is used extensively in the making of cooking pans.
Date posted: May 17, 2017. Answers (1)
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The flow chart below shows a sequence of chemical reactions starting with copper. Study it and answer the questions that follow.
In step 1, excess 3 M nitric (V) acid was added to 0.5 g of copper powder.
(i) State two observations which were made when the reactions was in progress.
(ii) Explain why dilute hydrochloric acid cannot be used in step 1.
Date posted: May 17, 2017. Answers (1)
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Below is a simplified diagram of the Downs Cell used for the manufacture of sodium. Study it and answer the questions that follow.
(i) What material is anode made of? Give a reason
(ii) What precaution is taken to prevent chlorine and sodium from re-combining?
(iii) Give any two uses of sodium
Date posted: May 17, 2017. Answers (1)
- The flow chart below shows steps used in the extraction of zinc from one of its ores. (Solved)
The flow chart below shows steps used in the extraction of zinc from one of its ores.
(a) Name the process that is used in step 2 to concentrate the ore.
(b) Name one use of zinc other than galvanizing
Date posted: May 16, 2017. Answers (1)
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The extraction of iron from its ores takes place in the blast furnace. Below is a simplified diagram of a blast furnace. Study it and answer the questions that follow.
Name
(i) One of the substance in the slag.
(ii) Another iron ore material used in the blast furnance.
(iii) One gas which is recycled.
Date posted: May 16, 2017. Answers (1)
- Below is a simplified diagram of Downs cell used for the manufacture of sodium. Study it and answer the questions that follow.
(Solved)
Below is a simplified diagram of Downs cell used for the manufacture of sodium. Study it and answer the questions that follow.
(i) What material is the anode made of? give a reason
(ii) What precaution is taken to prevent chlorine and sodium from re-combining?
Date posted: May 16, 2017. Answers (1)
- Study the flow chart below and answer the questions that follow. (Solved)
Study the flow chart below and answer the questions that follow.
(a) State the condition necessary for the reaction in step 2 to occur.
(b) Name: (i) Gas D (ii) One use of zinc
Date posted: May 16, 2017. Answers (1)
- The flow chart below shows a sequence of reactions starting with copper. Study it and answer the questions that follow. (Solved)
The flow chart below shows a sequence of reactions starting with copper. Study it and answer the questions that follow.
(i) Identify:
Gas P
Reagent Q
Solid R
(ii) State the observations made in steps 4 and 7.
Date posted: May 16, 2017. Answers (1)
- The flow chart below illustrates the industrial extraction of lead metal. Study it and answer the questions that follow. (Solved)
The flow chart below illustrates the industrial extraction of lead metal. Study it and answer the questions that follow.
(i) Name the ore that is commonly used in this process.
(ii) Explain what takes place in the roasting furnace.
(iii) Identify gas P.
Date posted: May 16, 2017. Answers (1)
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The flow chart below shows a sequence of reactions starting with iron. Study it and answer the questions that follow.
(i) Name the reagent and state the condition for the reaction in step I.
(ii) Give the name of the following: (I). Solid S (II) Solid V (III) Solid T
(iii) Give reasons for the colour change in step 2.
Date posted: May 16, 2017. Answers (1)
- The diagram below shows the extraction of sodium metal using the Downs cell. Study it and answer the questions that follow: (Solved)
The diagram below shows the extraction of sodium metal using the Downs cell. Study it and answer the questions that follow:
(i) Explain why in this process the sodium chloride is mixed with calcium chloride.
(ii) Why is the anode made of graphite and not steel?
(iii) State the properties of sodium metal that makes it possible for it to be collected as shown in the diagram.
iv) What is the function of the steel guaze cylinder?
v)Why is the anode made of graphite in this case instead of steel which is a better conductor of electricity?
vi)Give reasons why large quantities of electricity is required for this process
Date posted: May 16, 2017. Answers (1)