Ujian 1 Rate of Reaction

7/28/2019 Ujian 1 Rate of Reaction

1/13

SMKDBL JOM CHEMISTRY A1

SMK DATO BENTARA LUAR BATU PAHAT1st CURRICULUM EVALUATION 2009

CHEMISTRYFORM 5

1 HOUR

NAME: .............................................CLASS : ....................................

Section A

Instruction : Each question is followed by four options. Choose the best option for each question.Write your answers in answer form at the end of the questions at page 6.

1.

2.

The following are units of the rate of reaction exceptA g s -1 B g min -1 C mol s -1D mol dm -1

The graph below shows the volume of gas produced plotted against time.

Based on the graph, find the averagerate of reaction for the first two minutes.A 10.0 cm 3 min -1

B 20.0 cm 3 min -1

C 30.0 cm 3 min -1 D 40.0 cm 3 min -1

3.

4.

Which of these following reactions is classifyas fast reaction?I Ripening of tomatoesII Striking a matchIII Burning of petrol in a car engineIV The weathering of limestones by acid

rainA IV onlyB II and III onlyC II, III and IVonlyD I, II, III and IV

Which of the following cannot be used todetermine the rate of reaction?I Volume of gas released per unit timeII Change of colour intensity per unit

timeIII Mass of precipitate produced per unit

timeIV Increase in the mass of reactant per

unit timeA III onlyB IV onlyC I and II onlyD III and IV only

1 st Evaluaton Confidential

Volume of gas (cm 3)

60

40

20

Time (minute)1 2 3

50

30

10

1


2/13


1 st Evaluaton Confidential 2


3/13


5.

6.

The graph below shows the volume of carbon dioxide gas liberated plottedagainst time for the reaction betweenmarble and excess hydrochloric acid.

The volume of carbon dioxide remainsconstant after 4 minutes becauseA the mass of catalyst decreasesB all the marble has been used upC all the hydrochloric has been used upD the rate of reaction remained

constant

Which of the following best describe

the properties of catalyst?I A catalyst increases the rate of

collisionII A catalyst increases a quantity of

productIII A positive catalyst is used to

accelerate reactionsIV Only a small amount of catalyst

is needed to catalyze a reactionsA I and II onlyB I and III only

C II and IV onlyD III and IV only

7.

8.

Three experiments were conducted by agroup of students to investigate the reaction

between excess zinc, and the acids as shownin the table below. Experiment Hydrochloric acid

P25 cm 3 of 2.0 mol dm -3 hydrochloric acid

Q 50 cm3 of 1.5 moldm -3

hydrochloric acid

R 40.0 cm3 of 1.0 mol dm -3

sulphuric acid

The graphs obtained are shown below.

Which of the following represents the resultsof the experiments correctly?

P Q RA I II IIIB III I IIC II I IIID III II I

When the temperature decreases, the number of effective collisions also decreases becauseA the activation energy increasesB the average kinetic energy decreasesC the number of atoms increases when the

bonds are brokenD the particles collide more often increases

the activation energy


Volume of carbondioxide gas (cm 3)

2 4 6 Time (s)

Volume of carbondioxide gas (cm 3)

t Time (minute)

Experiment I

Experiment II

Experiment III

3


4/13


9.

10.

11.

Zinc powder reacts faster with hydrochloricacid than a zinc strip becauseA there is a layer of zinc oxide on the

zinc stripB the zinc powder has a larger total

surface areaC the particles of zinc powder have

more kinetic energyD the particles in the zinc strip packed

more closely together

The diagram shows an energy profilediagram.

Based on the above energy profile diagram,the amount of activation energy is..

A (Y X) kJ mol-1

B X kJ mol -1

C (X Y) kJ mol -1 D Y kJ mol -1

4 g magnesium powder is reacted in excessof dilute hydrochloric acid. It is found thatafter 0.5 minutes, 2.8 g of magnesium

powder is left as residue. What is theaverage rate of reaction for this reaction?[Relative atomic mass: Mg, 24]

A 0.05 mol min-1

B 0.01 mol min -1 C 0.1 mol min -1 D 0.2 mol min -1

12.

13.

5 g magnesium carbonate is placed in aconical flask on an electronic balance and25 cm 3 dilute hydrochloric acid is added.The change in mass is recoded at 30 sintervals. The results of the experimentare shown in the diagram below.

At what time was the rate of reaction thehighest?A 10 minB 20 minC 30 minD 40 min

In an experiment, zinc metal is mixedwith 50 cm 3 of acid. Which of thefollowing mixture will yield gas with thelowest initial rate of reaction?A 6 g of granulated zinc with

0.4 mol dm -3 ethanoic acid.B 6 g zinc powder with 0.4 mol dm -3

hydrochloric acid.C 12 g granulated zinc with 0.2 mol

dm -3 sulphuric acid.D 12 g of zinc powder with 0.2 mol

dm -3 hydrochlporic acid.


Energy

Reactants

X kJ mol -1

Y kJ mol -1

Products

Flask + contents

30

20

10

0

40

10 20 30 40Time (s)

4


5/13


14.

15.

Curve R in the following graph shows thedecomposition of 30 cm 3 of 0.50 moldm -3 of hydrogen peroxide by using 0.2 gof manganese(IV) oxide as catalyst at atemperature of 30 oC.

Which of the following experiments will produce curve S?

Volume of H 2O2 / cm 3

Concentration of H 2O2 / mol dm -3

A 30 0.60B 15 0.60C 30 0.40D 40 0.40

Which of the following statements aboutthe characteristic of a catalyst are true ?I Reacts specifically for a certain

reaction only.II Normally used in small quantity.III At the end of reaction catalyst

may change their physicalcharacter.

IV The catalyst use only to speed therate of reaction

A II and IV onlyB I, II and IV onlyC I, II and III onlyD I, II, III and IV

16.

17.

18.

Which of the following statement givesthe best explanation about the statementabove?A New bonds are easily formed.B Number of effective collisions

increases.C Bonds within the reactants are

easily brokenD Energy of reacting particles

increases because the activationenergy has been lowered.

The best definition for a catalyst is achemical compound that can change therate of chemical reaction andA is used widely in industrial fields.B does not change chemically at the

end of a reaction.C does not take part directly in a

reaction.D is a complex molecule that is

produced by plants.

Which of the following statements givesthe best explanation for the statementgiven above?A Kinetic energy of molecules

decreases.B Bonds are easier to break.C Activation energy is lowered.

D Chances to have effectivecollisions are increased.


Volume of oxygen (cm 3)

Time (min)

R

S

Increase in temperature willincrease the rate of reaction

Reducing the size of reactants willincrease the rate of reaction

5


6/13


19.

20.

The diagram shows an energy level for thereaction P + Q S. What is theactivation energy for this reaction?A 130 kJ mol -1

B 350 kJ mol -1 C 480 kJ mol -1

D 830 kJ mol -1

The equation above represents the Haber process. The rate of reaction increases if pressure increases because

A the kinetic energy of nitrogen gasmolecules and hydrogen gasmolecules increases.

B the activation energy is loweredunder high pressure.

C the covalent bonds in molecules N 2and H 2 are easily broken under high pressure.

D the concentration of nitrogen gasand hydrogen gas increases under high pressure.

21.

22.

23.

Which of the following will change E a toEa ?A Negative catalyst

B Positive catalystC PressureD Promoter

Food is stored in a refrigerator last longer than food stored in a kitchen cabinet

because.A the food particles have less kinetic

energyB the dehydration of food decreases

the temperature of foodC the concentration of food decreases

the surface areas of foodD the lower temperature decreases

the rate of the reaction of bacteriaon food.

Which of the following pairs are notcorrectly matched?

Process Catalyst A Haber IronB Ostwald NickelC Margarine NickelD Sulfuric acid Vanadium(V) oxide


Energy

P + Q

480 kJ 350 kJ

S

N2

(g) + 3H2

(g) 2NH3

(g)

Energy

P + Q

Ea

Ea

Ea

6


7/13


24. Which of the following statements is nottrue about the collision theory?A All the collisions of the particles

will produce a reaction.B The reaction will only occur when

the particles possess energy equalor more than E a .

C A greater surface area will producemore effective collisions amongthe particles.

D The rate of collision increases witha temperature rise.

25. 2 g magnesium ribbon is dissolved in anexcess of 0.1 mol dm -3 of hydrochloricacid to produce magnesium chloride andhydrogen. Which of the following factorswill produce a greater volume of hydrogen gas?A Use 3 g magnesium ribbon.B Use concentrated hydrochloric acidC Warm the solution of the mixture.D Use 2 g of magnesium powder.

Answer For Section A

Question Answer Question Answer Question Answer

1 11 21

2 12 22

3 13 23

4 14 24

5 15 256 16

7 17

8 18

9 19

10 20

Section B



8/13


Instruction: Answer all the questions in space provided.

1. (a) List all the factors affecting the rate of reaction.

.. ..............

........................................[2 marks]

(b) State the meaning of these following items;i. Rate of reaction,

......

..

[2 marks]i. Activation energy;

......

..

[2 marks]ii. Effective collision;

...

...[2 marks]

Time (s) 0 20 40 60 80 100 120 140 160 180 200

Volume of carbondioxide (cm 3 )

0.0 14.0 25.0 33.0 38.5 42.5 45.5 47.0 48.0 48.0 48.0

Table 1

2. Table 1 shows the results obtained from an experiment that is used to determine the rate of reaction between marble chips and hydrochloric acid. In this experiment, excess marble chips,CaCO 3 were reacted with 20 cm 3 of hydrochloric acid, HCl. The released carbon dioxide gas wasobtained through the downward displacement of water.[Relative atomic mass: Ca, 40; C, 12; O, 16; and 1 mole of gas occupies 24 dm 3 at roomtemperature and pressure]

(a) Write a chemical balanced equation for the reaction.



9/13


[1 mark ]

(b) Draw a graph of total volume of carbon dioxide gas against time basedon the results given in Table 1 .



10/13


[2 marks]

(c) Draw a labelled diagram that shows the set-up of the apparatus that is suitable for thisexperiment.

[2 marks]

(d) Calculate the average rate of reaction in the 2nd minute.

[1 marks]

(e) What is the rate of reaction at 1.0 minutes?

[2 marks]



11/13


3. Figure 2 shows the flow chart for the production of sulphuric acid in industries..

a. Give the name of process for the production of sulphuric acid as shown in Figure 2 .

...[1 mark]b. Name substance K .

.........[1 marks]

c. Sulphur trioxide could react directly with water to form sulphuric acid.Explain why it is not usually carried out.

...[1 mark]

d. Name the catalyst used in the conversion of J to sulphur trioxide.

...

[1 mark]e. Write chemical equation for the conversion of J to sulphur trioxide.

..

[1 mark]4. An experiment was conducted to find out the effect of temperature on the rate of reaction. 50 cm 3

of sodium thiosulphate solution 0.05 mol dm -3 at 30 oC was put into a 250 cm 3 conical flask.Then the conical flask was placed on an X sign on a piece of white paper.10 cm 3 of hydrochloric acid 1.0 mol dm -3 was added to the sodium thiosulphate solution andshaken. At the same time, the stop watch was started. The stop watch was stopped as soon as theX sign was no longer visible.

The same steps of the experiment were repeated for sodium thiosulphate solution which washeated to 35 oC, 40 oC, 45 oC, 50 oC,


Sulphur J Sulphur trioxide

K Sulphuricacid

Fertilizer heat(450 500) oC

1 atm

I II III IV V

Figure 2

11


12/13


(a) State the variables involved in this experiment.

Manipulated variables :

...

..

..

Method to manipulate the variable :

..

..

..

Responding variables :

..

..

.


.

.

..

How the variable responds? :

..

..

..

Fixed variables :

..

.

.


..

.....

..

[6 marks ]

JOM CHEMISTRY A1

SECTION A 25

SECTION B 25



13/13


TOTAL MARKS 50 Prepared by; KAMAL ARIFFIN B SAAIM SMKDBL, ,2009


Ujian 1 Rate of Reaction

Documents