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a) R – Melting,
V- Boiling point or vaporization,
W – Condesation
U – Freezing
b) Iodine
c) Exothermic
Slowing down particles release their kinetic energy as the gas condenses to liquid
johnmulu answered the question on April 5, 2017 at 11:51
- 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(Solved)
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)
- The curve below represents the variation of temperature with time pure and impure samples of a solid were heated separately.(Solved)
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)
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
Date posted: February 22, 2017. Answers (1)
- Distinguish between nuclear fission and nuclear fusion and describe how solid wastes containing radioactive substance should be disposed off. (Solved)
a) Distinguish between nuclear fission and nuclear fusion.
b) Describe how solid wastes containing radioactive substance should be disposed off.
Date posted: February 22, 2017. Answers (1)
- State two factors which determine the stability of an isotope.(Solved)
State two factors which determine the stability of an isotope.
Date posted: February 22, 2017. Answers (1)
- State two differences between chemical and nuclear reactions. (Solved)
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)
- Give the name of the first member of the alkene homologous series and Describe a chemical test that can be used to distinguish butanol from butanoic acid. (Solved)
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)
- State two uses of ethanol(Solved)
State two uses of ethanol other than as an alcoholic drink
Date posted: February 22, 2017. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- State two uses of the polymer polystyrene(Solved)
Give two uses of the polymer polystyrene
Date posted: February 22, 2017. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. 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)
- 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. Answers (1)
- a) What is the name given to a compound that contains carbon and hydrogen only?
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?
b) Hexane is a compound containing carbon and hydrogen.
i) What method is used to obtain hexane from crude oil
ii) State one use of hexane
Date posted: February 21, 2017. Answers (1)