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Give three factors that accelerate rusting
Date posted:
August 16, 2018
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10.26 g of aluminium sulphate were dissolved in 200cm3 water. Calculate the molar concentration of the sulphate ions in the solution (Relative formula mass of aluminium sulphate = 342).
Date posted:
August 15, 2018
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An oxide of silicon was found to contain 47% by mass silicon. What is the empirical formula of the oxide? (Si=28,O=16)
Date posted:
August 13, 2018
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Explain how a mixture of sulphur and sodium chloride can be separated into solid sulphur and sodium chloride
Date posted:
August 2, 2018
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Give one chemical test to distinguish between ethane and ethene.
Date posted:
July 7, 2018
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Why do cars in Mombasa rust faster than those in Kisumu?
Date posted:
July 7, 2018
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A student was stung by a bee and sodium hydrogen carbonate was applied to relieve the pain. Explain.
Date posted:
July 4, 2018
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Copper (II) oxide and charcoal are both black solids. Describe how you can distinguish them.
Date posted:
July 1, 2018
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Explain the following observations when burning magnesium is lowered into a gas jar of carbon(4) oxide it continues burning,but when burning zinc is lowered into a gas jar of carbon (4) oxide it does not burn.
Date posted:
June 24, 2018
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What is the difference between fractional distillation and fractional crystallization?
Date posted:
June 23, 2018
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What is the difference of alkali and alkaline?
Date posted:
June 22, 2018
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What mass of sodium hydroxide would be neededto neutralize exactly 200 cubic centimetre of a solution containing 49 grammes of sulphuric acid in dm^-3
Date posted:
June 18, 2018
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State the assumptions of capture recapture method of population size estimation.
Date posted:
May 19, 2018
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Explain why sodium hydroxide is preferred when making a setup to investigate the active part of air using a burning candle.
Date posted:
May 14, 2018
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Describe the process of obtaining nitrogen gas from air by fractional distillation of liquid air.
Date posted:
May 10, 2018
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What is Ostwald process?
Date posted:
May 5, 2018
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Write the chemical equation for reaction that takes place in the absorption tower in the contact process.
Date posted:
May 5, 2018
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Outline the five major processes of the contact process in the production of sulphuric acid.
Date posted:
May 5, 2018
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In the last stage of the solvay process, a mixture of sodium hydrogen carbonate and ammonium chloride is formed.
i.) State the method of separation used.
ii.) Write an equation showing how lime is slaked.
iii.) Name the by-product recycled in the above process.
Date posted:
May 2, 2018
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Solvay process is used to manufacture sodium carbonate.
a.) Name two raw materials.
b.) How is sodium carbonate obtained from sodium hydrogen carbonate.
c.) Name two main substances that are recycled.
Date posted:
May 2, 2018
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Describe a chemical test that can be used to distinguish between sodium carbonate and sodium hydrogen carbonate.
Date posted:
May 2, 2018
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Starting from calcium carbonate, describe how a solid sample of calcium sulphate can be prepared.
Date posted:
May 2, 2018
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A form four student accidentally mixed sodium carbonate and calcium carbonate. Describe how he would obtain a dry sample of sodium carbonate from the mixture.
Date posted:
May 2, 2018
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Explain how one would obtain pure sample of potassium carbonate crystals from a mixture of potassium carbonate and calcium carbonate.
Date posted:
May 1, 2018
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Describe how a sample of magnesium carbonate can be prepared using the following agents.
-Sodium carbonate
-Magnesium oxide
-Dilute hydrochloric acid
Date posted:
May 1, 2018
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Describe how a solid sample of lead (II) sulphate would be prepared using the following reagents.
. dilute nitric (V) acid
. solid lead (II) carbonate
. dilute sulphuric (VI) acid
Date posted:
May 1, 2018
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A sample of copper turning was found to be contaminated with copper ii oxide.describe how copper metal can be separated from the mixture
Date posted:
May 1, 2018
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A solution of tetrachloromethane burns colourless when propene gas is bubbled through it. What type of reaction takes place?
Date posted:
May 1, 2018
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Suggest a reason why BaSO4(a pigment made from sulphuric acid) would be
suitable in making paint for cars.
Date posted:
April 29, 2018
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Nitric v acid is manufactured by catalytic oxidation of ammonia gas
a. Name two raw materials other than ammonia that are used to manufacture the acid
b. Name the catalyst used.
c. Write an equation for reaction between nitric v acid and ammonia gas
d. sate one use of product in c
Date posted:
April 24, 2018