CHAPTER 1 : RATE OF REACTIONLarning Task 1.2 Problem Solving

To solve neumerical problems involving the rate of reactionIn an experiment, solid magnesium carbonate is added to dilute sulphuric acid. The gas evolved is collected in a burette. Volume of gas collected is recorded at intervals of 20 seconds. Table below shows the results obtained.

Time (s) 0 20 40 60 80 100 120 140 160 180Volume of gas (cm3) 0.00 38.00 54.50 63.50 68.50 71.50 73.00 73.00 73.00 73.00

a) Using the results in table plot a graph of the volume of gas evolved against time.b) Based on graph plotted, determine the average rate of reaction.

i) in the first 70 seconds ii) in the second minute iii) for the overall reaction.c) Based on the graph plotted, determine the instantaneous rate of reaction at

i) 30 seconds ii) 50 seconds iii) 70 secondsd) Compare the values of the instantaneous rates of reaction obtained in (c)

EFFECTIVE PRACTICE : A1. Calculate the average rate of reaction for the following reactions.

a) 25.0 cm3 of oxygen gas is collected in 2 minutes.

b) 1.5g of zinc reacted completely in 1.5 minutes.

2. What is the difference between the average rate of reaction and the rate of reaction at a given time.

3. Figure shows the graph obtained by a student in an experiment involving thereaction of excess magnesium powder withdilute hydrochloric acid.Based on figure answer the following questions.

a) When does the reaction stop?

b) When is half of the total amount ofHydrochloric acid reacted?

c) Determine the average rate of reaction i) Between 3 to 5 minutes

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ii) In the second minute.

d) What is the instantaneous rate of reaction at 3 minutes?

e) Sketch the graph of i) mass of magnesium against time ii) concentration of magnesium chloride solution against time.iii) concentration of hydrochloric acid against time.

LEARNING TASK 1.3 : Problem SolvingTo solve problems involving the factors affecting the rate of reaction.

1. Three sets odf experiments are carried out to study the rate of reaction between zinc and sulphuric acid. The table below shows the reacting conditions.

Set Reacting conditionsI 25 cm3 of 0.4 mol dm-3 sulphuric acid + 1g granulated zinc at room temperatureII 20 cm3 of 0.4 mol dm-3 sulphuric acid + 1g granulated zinc + 5 cm3 of 1 mol dm-3 copper (II)

sulphate solution at room temperature III 10 cm3 of 0.4 mol dm-3 sulphuric acid + 1g granulated zinc at 600C

a) i) How does the intial rate of reaction in set II differ from that of set I ?

ii) Suggest a reason for your answer in (a) (i).

b) i) Compare the time needed to collect 50 cm3 of gas in set I ?

ii) Give inference for your answer in (b) (i).

c) Arrange the maximum volume of hydrogen gas liberated in sets I, II and III in ascending order . How do you obtain your answer?

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d) On the same axes, sketch the graphs of the volume of hydrogen gas against time for i) sets I and II ii) sets I and III

mass of magnesium

2. In an experiment, 100cm3 of 1.0 mol dm-3 hydrochloric acid is added to 2.0g of 2.0excess magnesium ribbon. Figure shows the graph of mass of magnesium against time for this experiment.Draw on the same exes, the graph you would 0.8expect to obtain if the experiment was timerepeated using

a) 2.0g of excess magnesium ribbon and 50cm32.0 mol dm-3 hydrochloric acid

b) 2.0g of excess magnesium powder and 50cm3 2.0 mol dm-3 hydrochloric acid

EFFECTIVE PRACTICE : B

1. A student is preparing carbon dioxide gas in the laboratory by reacting dilute nitric acid with lumps of marble. Suggest three ways to speed up the production of the gas.

2. An experiment is carried out to study the effect of concentration of potassium thiosulphate solution on the rate of reaction between potassium thiosulphate solution and 2.0 mol dm-3 hydrochloric acid . The time taken for a fixed mass of sulphur formed is shown below.

Concentration of potassium thiosulphate solution (mol dm-3) 0.02 0.04 0.06 0.08 0.10

Time taken for a fixed mass of sulphurformed (s) 94.8 49.9 36.1 25.2 19.8

a) Write down the ionic equation for the reaction that occurred in this experiment.

b) How to ensure that a fixed mass of sulphur is formed in this experiment?

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c) i) Based on table above calculate the values of 1/time at different concentrations of potassium thiosulphate solution. Design a table to tabulate your answers.

ii) Plot a graph of concentrations of potassium thiosulphate solution against 1/time

iii) What can you deduce from the graph plotted?

d) Using the answer in ( c ) (iii), what is the relationship between the rate of reaction and the concentration of potassium thiosulphate solution?

3. A sample of aqueous hydrogen peroxide takes a few months to decomposed completely into oxygen and water. If a piece of platinum is immersed into the solution, the reaction is completed in a few minutes. Why?

EFFECTIVE PRACTICE : C1. a) What is meant

i) activition energy?

ii) effective collition?

b) Figure shows the energy profile diagram for the following reaction

N2(g) + O2(g) 2NO(g)Among the values r, s, t, u and v which is

the activation energy?

c) The rate of reaction depends on the magnitude of the activation energy for the reaction. Describe the relationship between the rate of reaction and its activation energy.

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2. The chemical equation below shows the reaction between hydrogen and chlorine.H2(g) + Cl2(g) 2HCl(g)

Do all collisions of hydrogen and chlorine molecules result in a reacton to produce hydrogen chloride molecules? Explain your answer.

3. Two sets of experiments are carried out to investigate the reaction between excess zinc carbonate wit sulphuric acid and nitric acid.

Set Mass of excess zinc carbonate powder Quantity of acidI 3g 20cm3 of 1 mol dm-3 sulphuric acidII 3g 20cm3 of 1 mol dm-3 nitric acid

a) Compare the initial rates of reactions for sets I and II.

b) Explain the answer in (a) using the collision theory.

4. Zn(s) + H2SO4(aq) ZnSO4(aq) + H2(g)

The energy profile diagram for the above reaction is shown as curve I in figure. Curve II for the same reaction can be obtained by changing the experimental conditions.

a) What is the change needed to be done on the original reaction to get curve II?

b) i) Which of the set, I or II, gives a higher rate of reaction?

ii) Explain your answer in (b)(i), using the collision theory.

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CHAPTER 2: CARBON COMPOUND

Learning Task 2.2 : Summarize the chemical reaction of alkanes

1. Figure shows a reaction map of methane. Collect data on the reactions of alkanes.Use the data to help you cmplete a copy of the map by filling the names and formulae of the products formed in each reaction.

2. Write balanced equations for the combustion of methane in limited and excess of oxygen.

3. Write equations to show how bromination of methane can produce four substitution products.

EFFECTIVE PRACTICE : B

1. a) using a named alkane , explain the meaning of terms ‘molecular formula’ and ‘structural formula’

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b) Write the names of the following hydrocarbons.

2. Dodecane is a member of the alkane famaly. It has 12 carbon atoms It melts at – 100C.

It boils at 2160C.

a) What is the molecular formula of dodecane ?

b) What physical state would you expect dodecane to be in at room temperature?

c) Methane has 1 carbon atom, melts at -1830C and boils at -1610C. Briefly explain the differences in melting and boiling points between these two alkanes.

d) Write an equation for the complete combustion of dodecane in oxygen.

3. Saturated hydrocarbons such as alkanes undergo sustitution reactions with halogens.Using methane and bromine , explain how a substitution reaction can occur between the two molecules.

ALKENES

EFFECTIVE PRACTICE : C

1. Fill in the blanks.Hexene is a member of the………………………….famly, which has the general

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formula…………………….. . The hexene molecule consists of

only…………….atoms and has a molecular formula of…………………. . The

molecule has carbon-hydrogen………………………bonds, carbon-carbon single

bonds and carbon-carbon …………………..bond. The presence of a

…………….bond makes hexene an …………………..hydrocarbon.

2. Describe and explain the trend in the boiling points of alkenes.

3. Part of the structure of a polymer is shown below.

a) Name the monomer used to form the above polymer.

b) Draw the structure of the monomer in (a)

4. A student is given a sample of a colourless organic liquid. His assignment is to demonstrate that the sample contains unsaturated molecules. Briefly describe the tests the student can carry out in the laboratory to show that the sample is an alkene.

EFFECTIVE PRACTICE : D

1. a student drew two structures as shown below.

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He believes the two structures are isomers of C3H6.a) What do you understand by the term ‘isomers’?

b) Is the student correct in identifying the two structures as isomers? Explain.

2. An Alkene molecule, X, has the molecular formula C5H10 . A student suggested its name as 2,2- dimethylpropene.

a) Darw the structure of this molecule.

b) How many isomers have the same molecular formula C5H10?

LEARNING TASK 2.7 : Predicting

To predict the reaction of propanols and butanols Figure shows summerizes the chemical reactions of ethanol.

Based on the reactions of ethanol, predict the reactions of propanols and butanols.

Combustion Dehydration

Propan-1-ol : Product Equation

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Propan-2-ol: Product Equation

Butan-1-ol : Product EquationButan-2-ol: Product Equation

2-methylpropan-1-ol: Product Equation

2-methylpropan-2-ol: Product Equation

EFFECTIVE PRACTICE : E

1. Write equations to show reactions of 2-methylpropan-1-ol withi) excess oxygen

ii) excess hot concentrated sulphuric acid.

iii) Acidified potassium dicromate(VI) solution.

2. Ethanol is manufactured in a large scale by hydration of ethene.a) With the help of an equation, explain what you understand by the term

‘hydration’.

b) Give the conditions for this hydration reaction.

c) Calculate the mass of ethanol that can be produced from 3.5 kg of ethene.[ RAM : C, 12; H, 1; O, 16]

EFFECTIVE PRACTICE : F

1. a) Name the elements found in carboxylic acids.

b)What is the general formula for the carboxylic acid family?

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c) Name the functional group of this homologous series.

2. One mole of carboxylic acid X has a mass of 74g.a) Name compound X.

b) Draw the structure of X.

c) Describe how X reacts with each of the following substances.i) calcium

ii) ii) amminia solution

iii) iii) zinc carbonate

I3. Figure shows a rreaction scheme compound P compound Q involving compond P. Compound P and Q have the same number of carbon atoms. II

Compound P is neutral, whereas compound Ethyl ethanoate Q is acidic.

a) Compound P is converted into compound Q by process I. Name process I.

b) What type of compound is ethyl ethanoate?

c) Compound P reacts with compound Q to form ethyl ethanoate. Name process II.

\LEARNING TASK 2.10 : AnalysingTo discuss the order in properties of homologus series.1. Table shows the boiling points of the first six members of the alcohol family.

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a) Use the data from the above table to plot a graph of boiling point against number of carbon atoms per molecule.

b) Discuss the order of the change in boiling points of members of the alcohol homologus series as the number of carbon atoms increases.

2. When a small piece of sodium metal is dropped into glacial ethenoic acid, a reaction occurs. The salt sodium ethanoate is produced together with hydrogen gas.

a) Write an equation for the reaction between ethanoic acid and sodium.

b) Can the other member ofcarboxylic acid homologus series react with sodium in similar manner?

c) Discuss how the order in chemical properties can be used to explain your answer in(b)

EFFECTIVE PRACTICE : G

1. Each of the following statements is incorrect but can be corrected by changing one ward. Underline thhe word that should be changed and give the correct word.

a) Esters contain the elements carbon, hydrogen and chlorine.

b) The functional group of ester famaly is the carboxyl group.

c) The carboxylic acid reacts with an alcohol in the presence of concentrated sulphuric acid to produce a salt and water.

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2. Name and draw the structural formula of the ester produced from a reaction between

a) methanol and butanoic acid

b) propan-1-ol and metanoic acid

3. Figure shows the reaction of an organic compound P.a) Identify compounds P,Q and R.

b) i) What types of reactions occur in I, II and III?

ii) Write an equation for each of the reactions.

c) i) State one physical property of compound R.

ii) Give one use of copound R in our everyday life.

EFFECTIVE PRACTICE : H

1. a) What is the functional group in glycerol?

b) What is fatty acid ?

c) What is the compound formed when glycerol combines with fatty acids?

1. Oils and fats are mixtures of many different esters. They are a good source of energy.

a) Why are oils and fats considered as sources of energy?

b) What are the differences between oils and fats?

2. Tripalmitin is a saturated fat whereas triolein is known as an unsaturated fat.a) Explain the meaning of ‘saturated fat’ and ‘unsaturated fat’.b) How can an unsaturated fat be converted into a saturated fat?

c) What are tne effects of eating diet high in saturated fats?

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d) What are the health benefits of consuming unsaturated fats such as palm oil?

EFFECTIVE PRACTICE : I

1.a) State the monomer for natural rubber.

b) Draw the structural formula for the monomer of natural rubber.

2. Explain how the addition of acid helps to coagulate latex.

3. a) What is valcanization ?

b) Compare the properties of vulcanized natural rubber with that of unvulcanized natural rubber.

c) How does vulcanization improve the properties of natural rubber?

CONCEPT MAP

Copy and complete the concept map below using the guides given.

CHAPTER 3 : OXIDATION AND REDUCTION

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LEARNING TASK 3.1 : Analysing

To identify oxidation and reduction based on changes in oxidation number.

a) Work out the oxidation numbers of each element in the following reactions.

i) 2H2 (g) + O2 (g) 2H2O(l)

ii) 2Na (s) + Br2 (g) 2NaBr (s)

iii) Pb (s) + 2Ag+ (aq) Pb2+ (aq) + 2Ag(s)

iv) Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g)

b) Identify i) The oxidized and the reduced substances in each reaction in (a). Give reasons

for your answer.

ii) The oxidizing agent and the reducing agent in each reaction in (a). State what happens to them.

EFFECTIVE PRACTICE : A

1.The following are the chemical equations of a few reactions.

I : 2NaBr(aq) + Pb(NO3)(aq) PbBr2(s) + 2NaNO3(aq)II: C2H4(g) + 3O2(g) 2CO2(g) + 2H2O(l)III: Mg(s) + CuCl2(aq) MgCl2(aq) + Cu(s)

a) Which of the reactions are redox reactions ? Give your reasons.

b) For each redox reaction,i) identify the oxidized substance and the reduced substance. Give the changes in

oxidation numbers of the substances involved.

ii) identify the oxidizing agent and the reducing agent.

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2. A Student added acidified potassium manganate (VII) solution to an iodide solution.a) Predict the observations obtained.

b) Write the oxidation and reduction half-equations.

c) Write the ionic equation to represent the redox reaction.

EFFECTIVE PRACTICE : B

1. State whether each of the following statements is true or false.a) Rusting is the corrosion of iron or steel.b) Unlike iron, other metals do not corrode.c) Rusting involves the oxidation of iron whereby it gains electrons to form rust.d) When iron is in contact with lead, rusting does not occur.e) Magnesium can provide sacrificial protection against rustingg.

2. a) What is the meaning of ‘metal corrosion’?

b) What is the relationship between the rate of corrosion and the electropositivity of the metal? Give reasons to your answer.

3. a) Give the two half –equations of oxidation and reduction during the rusting of iron.

b) State 4 ways whereby metals are used in controlling rusting. For each way, give one daily example.

4. Four different types of iron nails are exposed to the atmsphere for several weks. The following table shows the results.

Nail Initial mass of nail (g) Final mass of nail (g) Increase in the mass (g)

Untreated 4.00 5.16Dipped in salt solution 4.12 5.77Galvanized 4.23 4.25Colied with copper 4.26 5.65

a) Find the increase in the mass of each nail.b) Why is there an increase in mass?

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c) Which nail acts as a control?

d) Which nail shows the highest increse in mass? Explain this increase.

e) Whih nail is best protected from rusting? How do you come to this conclusion? How does the treatement given to the nail protect the nail from rusting?

5. a) Steel cans that are coated with tin are used in the canning industry. How can tin prevent steel from rusting?

b) Explain why canned food in a dented tin should not be consumed.

c) Using sacrifical protection is another way to prevent rusting. Give one example of a sacrifical metal and explain how it can prevent rusting.

LEARNING TASK 3.4 : Problem SolvingTo solve problems related to the reactivity series of metals with oxygen

Analyse each of the folowing situations. Predict whether any chemical reaction can take place. Give you reasons and suggest the products formed, if any.

a) Hydrogen gas is passed over hot tin(IV) oxide.

b) A mixture of lead powder and iron (II) oxide is heated strongly.

c) Steam is passed over hot zinc granules.

EFFECTIVE PRACTICE : C

1. Based on the following results, arrange aluminium, chromium and manganese in order of their reactivity, starting with the most reactive metal.

Chromium is produced when a mixture of chromium(II) oxide and aluminium is heated

When manganese is heated with aluminium oxide, no reaction takes place. Maganese can displace chromium from chromium(III) oxide.

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3. Steam is passed over hot metal X. The metal glows brightly and changes colour from grey to yellow when hot and white when cooled.

a) Compare the position of metal X with hydrogen in the reactivity series of metals with oxygen.

b) Identify metal X.

c) Explain the redox reaction that occurs.

EFFECTIVE PRACTICE : D

1. Give a suitable word or phrase for each of the following discriptions.a) A cell that produces electricity from redox reaction.

b) Chemical cells that cannot be discharge after use.

c) The electrode at which oxidation occurs in an electrolytic cell.

d) The electrode at which reduction occurs in an chemical cell.

2. a) Compare the conversion of energy in an electrolyte cell and a chemical cell.

b) How are electrons trnsferred in an electrolytic cell? Does this hold true for a chemical cell too?

3. Figure shows an electrlytic cell. Both X and Y are copper electrodes.

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a) Predict what is observed at electrode X.

b) Write an equation to represent the reaction at X.

c) State the type of reaction that occurs at Y.

d) Give the change of oxudation number that takes place at Y.

4. Figure shows the model of a cell in a lead-acid accumulator.a) Name the electrolyte in the cell.

b) Which electrode acts as the cathode? Which electrode acts as the anode?

c) What is the direction of the flow of electrons in the cell?

d) State the changes of oxidation number that take place at both electrodes.

e) Name another example of rechargeable cell.

CONCEPT MAP

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CHAPTER 4 : THERMOCHEMISTRY

LEARNING TASK 4.2 : Constructing energy level diagrams.

To construct energy diagrams for exothermic and endothermic reaction. Based on the following equations, construct energy level diagrams for the reactions.

a) Mg(s) + H2SO4(aq) MgSO4(aq) + H2(g) H = - 467 kJb) 2HgO (s) 2Hg(s) + O2(g) H = +182 kJc) CaCO3(s) CaO + CO2(g) H = +178 kJd) 2H2(g) + O2(g) 2H2O(l) H = - 572 kJe) Zn(s) + CuSO4(aq) ZnSO4(aq) + Cu(s) H = - 190 kJf) H2(g) + I2 (s) 2HI(g) H = +53 kJ

EFFECTIVE PRACTICE : A

1. What is meant by a) exothermic reaction?

b) endothermic reaction?

Give one example for each reaction.

2. State four differences between exothrmic and endothermic reactions.

3. Draw energy level digrams for the following reactions. a) S(s) + O2(g) SO2(g) H = - 297 kJ b) N2(g) + O2(g) NO(g) H = + 180 kJ

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4. Figure shows the energy level diagram for the reaction between methane and oxygen.

State four pieces of information that can be obtained from the above energy level diagram.

LEARNING TASK 4.4 : Problem Solving

To solve neumerical problems involving heat of precipitation[specific heat capacity of solution: 4.2 Jg -1 0C-1 Density of solution : 1 g cm-3]

1. In an experiment to determine the heat of precipitation of lead (II) sulphate, 50cm3 of 0.5 mol dm-1 lead (II) nitrate solution is added to 50 cm3 of 0.5 mol dm-3 sodium sulphate solution in a plastic cup. The following results are obtained.

Initial temperature of lead (II) nitrate solution = 28.00CInitial temperature of sodium sulphate solution = 28.00CHighest temperature reached when the two solutions are mixed = 30.50C

a) Calculate the heat of precipitation for lead(II) sulphate

b) If the experiment is repeated using 100cm3 of 0.5 mol dm-1 lead (II) nitrate solution and 100 cm3 of 0.5 mol dm-3 sodium sulphate solution, will the change in temperature remain the same? Explain your answer.

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2. The thermochemical equation for the precipitation of silver chloride is as follows: Ag+ (aq) + Cl- (aq) AgCl(s) H = - 65.5 kJ mol-1

Calculate the temperature change when 100 cm3 of 0.5 mol dm-3 silver nitrate solution is added to 100 cm3 of 0.5 mol dm-3 potassium chloride solution.

EFFECTIVE PRACTICE : B[specific heat capacity of solution: 4.2 Jg -1 0C-1 Density of solution : 1 g cm-3]

1. What is meant by ‘heat of precipitation’?

2. Draw energy level diagram for the following precipitation reactions.a) CaCl2(aq) + NaCO3(aq) CaCO3(s) + 2NaCl(aq) H = +12.6 kJ mol-1

b) Pb(NO3)2(aq) + K2SO4 (aq) PbSO4(s) + 2KNO3(aq) H = - 42 kJ mol-1

3. When iron (III) chloride solution is added to sodium hydroxide solution, a brown precipitate is fprmed. The thermochemical equation is given below.

Fe3+(aq) + 3OH-(aq) Fe(OH)3(aq) H = -10 kJ mol-1

In an experiment, a student mixes the two solutions shown below.

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a) Draw the energy level diagram for the reaction.

b) Calculate the number of moles of the following ions.i) iron(III) ions

ii) hydroxide ions

c) Calculate the heat given out in this experiment.

d) What is the change in temperature?

4. Explain why the heat of precipitation for the following reactions is the same.a) AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq) H = -65.5 kJ mol-1

b) AgNO3(aq) + KCl(aq) AgCl(s) + KNO3(aq) H = -65.5 kJ mol-1

5. When 50cm3 of 2.0 mol dm-1 magnesium nitrate solution at 28.00C is added to 50cm3 of 2.0 mol dm-1 sodium carbonate solution at 29.00C, the temperature of the mixture decreases to 23.00C.a) calculate the heat change in the experiment.

b) calculate the heat of precipitation of magnesium carbonate.

c) Draw the energy level diagram for the precipitation of magnesium carbonate.

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LEARNING TASK 4.5 : Problem Solving[specific heat capacity of solution: 4.2 Jg -1 0C-1 Density of solution : 1 g cm-3]

1. Excess aluminium powder is added to 100cm3 of 0.5 mol dm-1 lead (II) nitrate solution. The mixture is stirred using a thermometer. The results of the experiment are shown below. Initial temperature of lead (II) nitrate solution = 29.00C

Highest temperature of the mixture = 33.50CCalculate the heat of displacement of lead by aluminium. Draw the energy level diagram for the reaction.

2. In an experiment,excess magnesium powder is added to 50cm3 of 0.25 mol dm-1 iron(II) sulphate solution at 29.00C. The thermochemical equation is shown below.

Mg(s) + Fe2+(aq) Mg2+(aq) + Fe(s) H = - 80.64 kJ mol-1

What is the highest temperature reached in this experiment?

EFFECTIVE PRACTICE : C[specific heat capacity of solution: 4.2 Jg -1 0C-1 Density of solution : 1 g cm-3]

1. What is meant by ‘heat of displacement’?

2. Based on the thermochemical equation given, explain what is meant by ‘ H’. Draw the energy level diagram for the reaction.

Zn(s) + Cu2+(aq) Zn2+(aq) + Cu(s) H = -210 kJ mol-1

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3. Figure shows an experiment carried out to determine the heat of displacement.

Based on figure answer the following questions.a) Explain why the copper powder must added in excess.

b) Explain why using copper in the powder form is important in the experiment.

c) Calculate the heat given out by the experiment.

d) Calculate the heat of displacement for the reaction.

e) What will happen to the change in temperature if the concentration of silver nitrate solution is doubled without changing its volume?

LEARNING TASK 4.6 : Problem Solving[specific heat capacity of solution: 4.2 Jg -1 0C-1 Density of solution : 1 g cm-3]To solve the neumerical problems involving heat of neutralisation.

1. In an experiment to determine the heat of neutralisation between hydrochloric acid and ammonia solution, 50cm3 of 1.0 mol dm-3 hydrochloric acid is added to 50cm3 of 1.0 mol dm-3 of ammonia solution. The temperature increases from 29.00C to 35.50C. Calculate the heat of neutralisation.

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2. The energy level diagram of a neutralisation reaction is shown in figure.a) When 100cm3 of 1.0 mol dm-3 sulphuric acid is added to 100cm3 of 1.0 mol dm-3 sodium hydroxide solution, what is the change in temperature?

b) When 100cm3 of 0.5 mol dm-3 sulphuric acid ia added to 100cm3 of 1.0 mol dm-3 sodium hydroxide solution, does the temperature change remain in the same as in (a)? Explain your answer.

3. The thermochemical equation for the reactio between ethanoic acid and sodium hydroxide solution is given below.CH3COOH(aq) + NaOH(aq) CH3COONa(aq) + H2O(l) H= -55 kJ mol-1

Calculate the heat given out when 200 cm3 of ethanoic acid is added to 100 cm3 of sodium hydroxide solution. Both solution have a concentration of 0.5 mol dm-3.

EFFECTIVE PRACTICE : D[specific heat capacity of solution: 4.2 Jg -1 0C-1 Density of solution : 1 g cm-3]

1. What is meant by ‘heat of neutralisation’?2. The thermochemical equations for the reactions of two strong acids with sodium hydroxide solution are shown below.

HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l) H = -57 kJ H2SO4(aq) + 2NaOH(aq) Na2SO4(aq) + 2H2O(l) H= -114 kJ

Explain why there is a difference in the values of H.

3. When sodium hydroxide solution and hydrochloric acid are mixed together, a rise in temperature is noted . The volume of each solution is 100cm3 and their concentration is 1.0 mol dm-3. The heat produced is calculated as 5.7 kJ.

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a) Calculate the heat of neutralization.

b) If the hydrochloric acid is replaced by nitric acid, predict the value of heat of neutralization. Explain.

LEARNING TASK 4.8 : Problem SolvingTo solve neumerical problems involving heat of combustion[specific heat capacity of solution: 4.2 Jg -1 0C-1 Density of solution : 1 g cm-3 . RAM H, 1; C, 12; O, 16]1. The following results are obtained by a student in an experiment to determine heat of cumbustion of ethanol.Volume of water used = 200 cm3

Initial temperature of water = 28.5 0CHighest temperature of water reached = 53.5 0C Mass of spirit lamp and ethanol before combustion = 189.55 gMass of spirit lamp and ethanol after combustion = 188.80 g

Based on the results, calculate the heat of combustion for ethanol and hence construct the energy level diagram for the combustion of ethanol.

2. When 1 mole of butanol is burnt in excess of oxygen, 2600 kJ of heat is produced. Calculate the mass of butanol needed to burn completely in oxygen in order to raise the temperature of 250 cm3 of water by 300C.

3. The thermochemical equations for the combustion of ethanol is as follows:C2H5OH(l) + 3O2(g) 2CO2(g) + 3H2O(l) H = - 1376 55 kJ mol-1

If the heat given out by 2.3g of ethanol is used to heat 500cm3 of water, calculate the rise in temperature of water.

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SEKOLAH MENENGAH KEBANGSAAN SEREMBAN JAYA

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NOTA DAN LATIHAN

MATA PELAJARAN CHEMISTRY

TINGKATAN 4 / 5

NAMA………………………………………………………………….

TINGKATAN………………………………………………………….

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