a) Ethene
b) When acidified potassium manganate (VII) is added to butanol and the mixture is warmed, it turns from purple to colourless. However, with butanoic acid acidified potassium manganate (VII) remains purple.
johnmulu answered the question on February 22, 2017 at 05:17
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State two uses of ethanol
(Solved)
State two uses of ethanol other than as an alcoholic drink
Date posted:
February 22, 2017
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Answers (1)
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Cotton is natural polymer. State one advantage and one disadvantage of this polymer.
(Solved)
Cotton is natural polymer. State one advantage and one disadvantage of this polymer.
Date posted:
February 22, 2017
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Answers (1)
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Describe two chemical tests that can be used to distinguish ethanol from ethanoic acid
(Solved)
Describe two chemical tests that can be used to distinguish ethanol from ethanoic acid
Date posted:
February 22, 2017
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Answers (1)
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State two uses of the polymer polystyrene
(Solved)
Give two uses of the polymer polystyrene
Date posted:
February 22, 2017
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Answers (1)
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Two organic compounds P and Q decolourise acidified potassium manganate (VII) solution, but only P reacts with sodium metal to give a colourless gas.
(Solved)
Two organic compounds P and Q decolourise acidified potassium manganate (VII) solution, but only P reacts with sodium metal to give a colourless gas. Which homologous series does compound P belong? Give a reason.
Date posted:
February 22, 2017
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Answers (1)
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Explain why the solubility of ethane in water is lower than of ethanol
(Solved)
Explain why the solubility of ethane in water is lower than of ethanol
Date posted:
February 22, 2017
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Answers (1)
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What name is given to the process by which alcohol is formed from a carbohydrate
(Solved)
What name is given to the process by which alcohol is formed from a carbohydrate
Date posted:
February 22, 2017
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Answers (1)
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The use of CFCs has been linked to depletion of the ozone layer.
(Solved)
The use of CFCs has been linked to depletion of the ozone layer.
a) What does CFC stand for?
b) Explain the problem associated with the depletion of the ozone layer
c) State another environmental problem caused by CFCs
Date posted:
February 22, 2017
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Answers (1)
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Some animal and vegetable oils are used to make margarine and soap. Give the reagent and conditions necessary for converting the oils into:
(Solved)
Some animal and vegetable oils are used to make margarine and soap. Give the reagent and conditions necessary for converting the oils into:
a) Margarine
b) Soap.
Date posted:
February 22, 2017
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Answers (1)
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Name the process that takes place when:....
(Solved)
Name the process that takes place when:
i) Crystals of zinc nitrate change into solution when exposed to air
ii) An alcohol reacts with an organic acid in the presence of a catalyst to form a sweet smelling compound.
Date posted:
February 21, 2017
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Answers (1)
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Explain why the boiling point of ethanol is higher than that of hexane
(Solved)
Explain why the boiling point of ethanol is higher than that of hexane (Relative molecular mass of ethanol is 46 while that of hexane is 86)
Date posted:
February 21, 2017
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Answers (1)
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The boiling point of ethanol, propanol and butanol are 78oC, 97.2oC and 117o
(Solved)
The boiling point of ethanol, propanol and butanol are 78oC, 97.2oC and 117oC. Explain this trend
Date posted:
February 21, 2017
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Answers (1)
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Pentane and ethanol are miscible. Describe how water could be used to separate a mixture of pentane and ethanol
(Solved)
Pentane and ethanol are miscible. Describe how water could be used to separate a mixture of pentane and ethanol
Date posted:
February 21, 2017
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Answers (1)
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State the observation that would be made when a piece of sodium metal is placed in samples of:
(Solved)
State the observation that would be made when a piece of sodium metal is placed in samples of:
i) Pentane
ii) Pentanol
Date posted:
February 21, 2017
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Answers (1)
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Name one natural fibre and give one advantage of synthetic fibres over natural fibres.
(Solved)
a) Name one natural fibre
b) Give one advantage of synthetic fibres over natural fibres.
Date posted:
February 21, 2017
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Answers (1)
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a) Name the raw material from which sodium is extracted.
b) Give a reason why sodium is extracted using electrolysis
c) Give two reasons of sodium metal
(Solved)
a) Name the raw material from which sodium is extracted.
b) Give a reason why sodium is extracted using electrolysis
c) Give two reasons of sodium metal
Date posted:
February 21, 2017
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Answers (1)
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One of the ores of copper has the formula, CuFeS2.
Describe how iron in the ore is removed during extraction of copper metal.
(Solved)
One of the ores of copper has the formula, CuFeS2.
a) Describe how iron in the ore is removed during extraction of copper metal.
b) State two environmental problems associated with extraction of copper metal
Date posted:
February 21, 2017
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Answers (1)
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Aluminium is both malleable and ductile....
(Solved)
Aluminium is both malleable and ductile
a) What is meant by?
i) Malleable
ii) Ductible
b) State one use of alumunium based on:
i) Malleability
ii) Ductility
Date posted:
February 21, 2017
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Answers (1)
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a) Explain why the metals magnesium and aluminium are good conductors of electricity
b) Other than cost, give two reasons why aluminium is used for making electric cables while magnesium is not.
(Solved)
a) Explain why the metals magnesium and aluminium are good conductors of electricity
b) Other than cost, give two reasons why aluminium is used for making electric cables while magnesium is not.
Date posted:
February 21, 2017
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Answers (1)
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In the industrial extraction of lead metal, the ore is first roasted in a furnace.
(Solved)
In the industrial extraction of lead metal, the ore is first roasted in a furnace. The solid mixture obtained is then fed into another furnace together with coke, limestone and scrap iron. State the function of each of the following in this process:
a) Coke
b) Limestone
c) Scrap iron.
Date posted:
February 21, 2017
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Answers (1)