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State and explain the observations made when excess ammonia gas reacts with chlorine
Date posted:
February 10, 2017
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Name the process which takes place when:
a) Solid carbon (IV) oxide (dry ice) changes directly into gas
b) A red litmus paper turns white when dropped into chlorine water.
c) Propene gas molecules are converted into a giant molecule
Date posted:
February 10, 2017
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The reaction between hot concentrated sodium hydroxide and chlorine produces sodium chlorate (V), sodium chloride and water.
a) Write the equation for the reaction
b) Give one use of sodium chlorate (V)
Date posted:
February 10, 2017
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Calcium oxide can be used to dry ammonia gas.
(a) Explain why calcium oxide is not used to dry hydrogen chloride gas
(b) Name one drying agent for hydrogen chloride gas
Date posted:
February 10, 2017
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The following two tests were carried out on chlorine water contained in two test-tubes:
a) A piece of blue flower was dropped into the first test-tube. Explain why the flower ached.
b) The second test-tube was corked and exposed to sunlight. After a few days, it was found to contain a gas that rekindled a glowing splint. Write an equation for the reaction which produced theas.
Date posted:
February 10, 2017
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A sample of hydrogen chlorine was dissolved in water to make 250 cm3 of solution 25 cm3 of the solution required 46 cm3 of 11.0 M sodium hydroxide for complete neutralization
i) Calculate the number of moles of hydrochloric acid in 25 cm3 of solution
ii) Determine the mass of hydrogen chloride that was dissolved to make 250 cm3 of solution (Cl = 35.5, H = 1.0)
Date posted:
February 7, 2017
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In an experiment, sulphur (IV) oxide was dissolved in water to form solution L.
i) What would be observed if a few drops of barium nitrate solution were immediately added to solution L?
ii) Write an ionic equation for the reaction that occurred between solution L and aqueous barium nitrate in (i) above.
Date posted:
February 7, 2017
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What would be observed if sulphur (IV) oxide is bubbled through acidified potassium manganate (VII)?
Date posted:
February 7, 2017
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Name two reagents that can be used to prepare hydrogen sulphide in the laboratory
Date posted:
February 7, 2017
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a) State the observation made at the end of the experiment when a mixture of iron powder and sulphur is heated in a test tube
b) When a mixture of iron powder and sulphur is heated, it glows more brightly than that of iron fillings and sulphur. Explain this observation
Date posted:
February 7, 2017
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When hydrogen sulphide gas was bubbled into an aqueous solution of iron (III) chloride, a yellow precipitate was deposited.
a) State another observation made
b) Write an equation for the reaction that took place
c) What type reaction was undergone by hydrogen sulphide in this reaction?
Date posted:
February 7, 2017
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In an experiment to study the properties of concentrated sulphuric (IV) acid, a mixture of the acid and wood charcoal was heated in a boiling tube.
a) Write the equation of the reaction that took place in the boiling tube
b) Using oxidation numbers, show that reduction and oxidation reactions took place in the boiling tube.
Date posted:
February 7, 2017
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In an experiment, a gas jar containing moist sulphur (IV) oxide was inverted over another gas jar containing hydrogen sulphide gas.
a) state and explain the observation that was made
b) state the precaution that should be taken when carrying out this experiment
Date posted:
February 7, 2017
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In an experiment, sulphur (IV) oxide gas was bubbled into water followed by chlorine gas. The resulting clear solution gave a white precipitate when mixed with acidified barium chloride solution. Explain these observations.
Date posted:
February 6, 2017
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Describe a simple laboratory experiment that can be used to distinguish between sodium sulphide and sodium carbonate.
Date posted:
February 6, 2017
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A certain matchstick head contains potassium chlorate and sulphur. On striking, the two subtances react to produce sulphur (IV) oxide and potassium chloride. Explain the environmental effect of using such matches in large numbers.
Date posted:
February 6, 2017
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When a solid sample of sulphur is heated in a test tube, it changes into a liquid which flows easily. On further heating, the liquid darkens and does not flow easily. Explain these observations.
Date posted:
February 6, 2017
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In an attempt to prepare sulphur (IV) oxide gas, dilute sulphuric (VI) acid was reacted with barium sulphite. The yield of sulphur (IV) oxide was found to be negligible. Explain
Date posted:
February 6, 2017
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On heating a pale green solid K, carbon (IV) oxide gas and black solid M were formed. On reacting K with dilute hydrochloric acid, carbon (IV) oxide gas and green solution S were formed. When excess aqueous ammonia was added to solution S, a deep blue solution was formed.
a) Identify the cation in solid K
b) Identify the two anions in solution S
Date posted:
February 6, 2017
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Describe how formation of nitrogen (II) oxide in the internal combustion engine leads to gaseous pollution.
Date posted:
February 6, 2017
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Give a reason why nitrogen (II) oxide is not formed at room temperature.
Date posted:
February 6, 2017
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Describe the process by which Nitrogen is obtained from air on a large scale.
Date posted:
February 6, 2017
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The use of materials made of lead in roofing and in water pipes is being discouraged. State:
i) Two reasons why these materials have been used in the past
ii) One reason why their use is being discouraged
Date posted:
February 6, 2017
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Explain why a high temperature is required for nitrogen to react with oxygen.
Date posted:
February 6, 2017
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Nitrogen (II) oxide and nitrogen (IV) oxide are some of the gases released from car exhaust pipes. State how these gases affect the environment.
Date posted:
February 6, 2017
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Concentrated nitric (V) acid was added to Iron (II) sulpahate acidified with dilute sulphuric (VI) acid the mixture heated. The solution turned from pale green to yellow with evolution of brown gas. Explain these observations.
Date posted:
February 6, 2017
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State and explain the observations that would be made if a sample of sulphur is heated with concentrated nitric (V) acid.
Date posted:
February 3, 2017
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Ethane gas was reacted with 1 mole of bromine gas. State one observation made during this reaction.
Date posted:
February 3, 2017
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What condition could cause a poisonous gas to be formed when kerosene is burnt? Explain
Date posted:
February 3, 2017
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Describe how solid sample of potassium sulphate can be prepared starting with 200 cm3 of 2M potassium hydroxide.
Date posted:
February 3, 2017