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The set-up below shows how gas A was prepared and reacted with heated magnesium.
(a) Give a reason why it is not advisable to heat magnesium before heating ammonium nitrite.
(b) (i) Identify gas A.
(ii) Write a chemical equation for the reaction between gas A and magnesium.
Date posted:
March 29, 2019
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When 25cm³ of 0.5M HCl is added to 25cm³ of 0.5M NaOH the temperature of the solution rose from 230C to 260C. Given that the density of the solution is 1gcmˉ³ and its specific heat capacity is 4.2Jgˉ¹Kˉ¹.
(a) Determine the amount f heat evolved that caused the temperature rise.
(b) Work out the molar enthalpy of neutralization for this reaction.y is 4.2Jgˉ¹Kˉ¹.
Date posted:
March 29, 2019
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Write down the property of concentrated sulphuric (VI) acid shown in the following reactions.
Date posted:
March 29, 2019
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The set-up was used to prepare carbon (IV) oxide and investigate its properties.
(a) Write an equation for the reaction in vessel B.
(b) What is the role of sodium hydroxide solution in the set-up?
(c) What would be observed if a burning splint is introduced at jet C?
Date posted:
March 29, 2019
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The formula for cane sugar is (C12H22O11). Use an equation to show what happens when sugar is added to conc.Sulphuric (VI) acid.
Date posted:
March 29, 2019
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20cm³ of a dibasic acid required 25cm³ of 0.1M NaOH for complete neutralization.
(a) How many moles of sodium hydroxide reacted with the dibasic acid?
(b) Calculate the concentration of the dibasic acid in moles per litre.
Date posted:
March 29, 2019
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When a compound X was heated, a brown gas and a black residue were produced. Give the formula of:
(i) The brown gas.
(ii) The black residue.
Date posted:
March 29, 2019
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0.92g of ethanol were found to burn in excess air producing a temperature rise of 32.5oC in 200cm3 of water(C=12.0,H=1.0,O=16.0) Density of water is 1g/cm3, specific heat capacity of water is 4.2KjKg-1K-1.
(a) Write the equation for the combustion of ethanol.
(b) Determine the molar heat of combustion of ethanol
Date posted:
March 29, 2019
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The structure of synthetic rubber is shown below;
a) Determine the relative molecular mass of a polymer made of 250 monomers.
(c=12,H=1 and Cl=35.5)
b) Give one advantage of natural polymers over synthetic ones.
Date posted:
March 29, 2019
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The diagram below shows electrolysis of dilute copper (II) sulphate solution using copper electrodes;
a) State the observations made at electrode A and B
b) Write the equation of reaction at electrode A
Date posted:
March 29, 2019
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Below is a simplified process for manufacture of sodium carbonate by Solvay process.
a) Name substance M.
b) Name the process taking place in step II.
c) Write an equation for the reaction in step III.
d) What is the fate of ammonium chloride in the solvay process.
Date posted:
March 29, 2019
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State and explain the trend in the boiling points of group (VII) elements down the group.
Date posted:
March 29, 2019
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Study the reaction below and answer the questions that follow.
a) State and explain the observation made when a mixture at equilibrium is heated.
b) If pressure is exerted at the mixture at equilibrium, what observation will be made?
Date posted:
March 29, 2019
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In reference to carbon (IV) oxide, distinguish between covalent bonds and Van der Waals forces.
Date posted:
March 29, 2019
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Using dots (.) and crosses (x) to represent electrons, show the bonding in hydroxonium ion (H=1 O=8).
Date posted:
March 29, 2019
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Explain why water molecule is capable of reacting with hydrogen ion (H+) to form hydroxonium ion (H3O+).
Date posted:
March 29, 2019
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Study the diagram below and answer the questions that follow
a) Name particles A and B
b) What property of B makes it not to be deflected by magnetic/electric field
Date posted:
March 28, 2019
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Compare the atomic sizes of sodium and magnesium. Explain.
Date posted:
March 28, 2019
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In an experiment, two pieces of iron sheets were wrapped in each case with zinc and copper metal sheets as shown below.They were left in the open for some months.
State and explain the observations made in the experiments; (I), (II)
Date posted:
March 28, 2019
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Name the chief ore of iron and write its formula
Date posted:
March 28, 2019
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Name the following processes;
a) When anhydrous calcium chloride is left in an open beaker overnight a solution was formed.
b) When sodium carbonate decahydrate crystals are left in an open beaker for some days it turned into a powder.
Date posted:
March 28, 2019
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Name the following organic compounds.
Date posted:
March 28, 2019
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The diagram below represents a method of separation used to separate two liquids A and B. use it to answer the questions that follow
a) Name two properties that makes it possible for the two liquids to be separated.
b) Give one alternative method that may be used to separate the two liquids.
Date posted:
March 28, 2019
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60cm³ of oxygen gas diffused through a porous hole in 50 seconds. How long will it take 80cm³ of sulphur (IV) oxide to diffuse through the same hole under the same conditions (S = 32, O = 16).
Date posted:
March 28, 2019
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Starting with solid lead (II) carbonate, briefly describe how a sample of lead (II) chloride can be prepared.
Date posted:
March 28, 2019
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The formulae below belong to 2 cleansing agents.
(a) Which of the two cleaning agents would lather readily with hard water?
(b) State one disadvantage of the continued use of cleansing agent II.
(c) Write the formula of the compound formed when cleansing agent I is used with water containing Mg2+ ions.
Date posted:
March 28, 2019
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When one mole of hydrocarbon M was completely burned in air, four moles of carbon (IV) oxide and three moles of water vapour were formed.
a) Work out the formula of the hydrocarbon.
b) Draw and name two structural formula of hydrocarbon M.
Date posted:
March 28, 2019
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The diagram below represents a section of the hydrochloric acid manufacturing plant.
(a) Name Y.
(b) State the role played by glass beads.
(c) Chlorine reacts with hydrogen sulphide gas according the equation shown below:
From the equation identify the oxidizing agent.
Date posted:
March 28, 2019
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a) Explain why hydrogen gas has been replaced by helium in filling aeroplane tyres.
b)Hydrogen gas is bubbled through oil in presence of a catalyst to yield fats.
(i) Name a suitable catalyst used in the above process.
(ii) What name is given to the above process.
Date posted:
March 28, 2019
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Potassium has two isotopes as shown below;
isotope 
and a radioactive 
(a) State how the two isotopes differ.
(b) The half-life of is 1.3 x 109 years. Determine how long it would take for 4g of the isotope to decay to 1g.
c)undergoes beta decay to form an isotope of calcium. Write the equation for this decay.
Date posted:
March 28, 2019