Curve II. This is because pure substances have sharp melting and boiling points as shown by the flat regions of curve II
johnmulu answered the question on April 5, 2017 at 08:28
- 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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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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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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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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Give two uses of the polymer polystyrene
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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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.
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Date posted: February 22, 2017. Answers (1)
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a) Margarine
b) Soap.
Date posted: February 22, 2017. Answers (1)
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(Solved)
Name the process that takes place when:
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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. Answers (1)
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b) Hexane is a compound containing carbon and hydrogen. (Solved)
a) What is the name given to a compound that contains carbon and hydrogen only?
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i) What method is used to obtain hexane from crude oil
ii) State one use of hexane
Date posted: February 21, 2017. Answers (1)
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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. Answers (1)
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The boiling point of ethanol, propanol and butanol are 78oC, 97.2oC and 117oC. Explain this trend
Date posted: February 21, 2017. Answers (1)