a) pens 4 and 5
b) pens 2 and 3
c) Yellow and red
johnmulu answered the question on April 5, 2017 at 12:19
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The set-Up below represents the apparatus that may be used to separate a mixture of two miscible liquids C and D whose boiling points are 80oC and 110oC.
a) Name B
b) What is the purpose of the thermometer?
c) Which liquid was collected in the test tube?
Date posted: April 5, 2017. Answers (1)
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The diagram below shows the relationships between the physical state of matter. Study it and answer the questions that follow.
a) Identify the processes R, V, W and U.
b) Name one substance which can undergo the process represented by S and T
c) Explain whether process W is exothermic or endothermic
Date posted: April 5, 2017. Answers (1)
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In an experiment to separate a mixture of two organic liquids, Liquid M (b.p 56oC) and liquid N (b.p.118oC), a student set up the apparatus shown below
a) Identify two mistakes in the set-up.
b) What method would the student use to test the purity of the distillates obtained?
Date posted: April 5, 2017. Answers (1)
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The curve below represents the variation of temperature with time pure and impure samples of a solid were heated separately.
Which curve shows the variation in temperature for pure solid? Explain.
Date posted: April 5, 2017. Answers (1)
- a) Distinguish between a neutron and a proton.
b) What is meant by a radioactive substance
c) State two dangers associated with radioactive substance in the environment(Solved)
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b) What is meant by a radioactive substance
c) State two dangers associated with radioactive substance in the environment
Date posted: February 22, 2017. Answers (1)
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b) Describe how solid wastes containing radioactive substance should be disposed off.
Date posted: February 22, 2017. Answers (1)
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State two factors which determine the stability of an isotope.
Date posted: February 22, 2017. Answers (1)
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State two differences between chemical and nuclear reactions.
Date posted: February 22, 2017. Answers (1)
- M grammes of a radioactive isotope decayed to 5 grammes in 100 days
The half-life of the isotope is 25 days(Solved)
M grammes of a radioactive isotope decayed to 5 grammes in 100 days
The half-life of the isotope is 25 days
a) What is meant by half-life?
b) Calculate the initial mass M of the radioactive isotope.
Date posted: February 22, 2017. Answers (1)
- An alkanol has the following composition by mass: Hydrogen 13.5%, oxygen 21.6% and carbon 64.9%
Determine the empirical formula of the alkanol (C = 12.0: H = 1.0; O = 16.0)(Solved)
An alkanol has the following composition by mass: Hydrogen 13.5%, oxygen 21.6% and carbon 64.9%
Determine the empirical formula of the alkanol (C = 12.0: H = 1.0; O = 16.0)
Date posted: February 22, 2017. Answers (1)
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a) Give the name of the first member of the alkene homologous series
b) Describe a chemical test that can be used to distinguish butanol from butanoic acid.
Date posted: February 22, 2017. Answers (1)
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State two uses of ethanol other than as an alcoholic drink
Date posted: February 22, 2017. Answers (1)
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Date posted: February 22, 2017. Answers (1)
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Date posted: February 22, 2017. Answers (1)
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Date posted: February 22, 2017. 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. Which homologous series does compound P belong? Give a reason.
Date posted: February 22, 2017. Answers (1)
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Explain why the solubility of ethane in water is lower than of ethanol
Date posted: February 22, 2017. Answers (1)
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Date posted: February 22, 2017. Answers (1)
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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. Answers (1)
- 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. Answers (1)