PAPER 2 STRUCTURE

Chemistry Intensive Revision Program - Set 1

SEKOLAH TINGGI MELAKA

(Super Thinkers Module)

CHEMISTRY

PROGRAM ULANGKAJI INTENSIF

(PUI)

(Intensive Revision Program-IRP)

Panitia Sains

(Kimia)

MELIORA HIC SEQUAMUR

KE ARAH KECEMERLANGAN PENDIDIKAN

PAPER 2 STRUCTURE

SECTION A

1Graph 1 shows the temperature against time of solid substance X when heated. Substance X is an organic compound and flammable.

GRAPH 1(a) Draw a diagram of the set-up of the apparatus used to determine the melting point of substance X.

[ 2 marks]

(b) (i)State the melting point of substance X

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

[ 1 mark]

(ii)What is the state of matter of substance X at :

PQ : .....................................................................................................................................................

RS : ....................................................................................................................................................

[ 2 marks]

(iii) Explain why the temperature remains constant from Q to R.

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

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

[ 2 marks]

(iv) State how the movement of substance X particles changes between R and S

during heating.

[ 1 mark]

(c) If substance X is cooled to the room temperature without stirring, draw the graph of temperature against time obtained.

[ 2 marks]

(d) Identify subtance X

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

[ 1 mark]

2Diagram 2 shows part of the Periodic Table of Elements.V,W,X,Y and Z do not represent the actual symbol of the elements.

1

18

21314151617

WXVZ

Y

DIAGRAM 2

(a) Write the electron arrangement of V ion.

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

[1 mark ]

(b)(i)Which of the element is not chemically reactive.

.

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

[1 mark ]

(ii)Explain your answer in (b)(i).

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

[1 mark ](c)V and Y are located in the same group in the Periodic Table of Elements.

(i)Which of the element is more reactive?

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

[1 mark ]

(ii)Explain your answer in (c)(i).

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

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

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

[3 marks]

(d)Y reacts with iron to form a compound.(i) State one property of the compound formed.

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

[1 mark] (ii) Draw a labeled the set up of apparatus of the reaction between Y and iron, Fe

[ 2 marks]

3 The table 3 shows melting point, boiling point and electrical conductivity of substance P, Q, R, and T .

\Substance

Melting point (oC)Boiling point (oC )Electrical conductivity

SolidMolten

P

8051460NoYes

Q

15492950YesYes

R

-210-153NoNo

T

-759NoNo

Table 3(a) Which of the substances is a metal ?

.

[1 mark]

(b) (i) state the type of particle in substance P ?

..

[1 mark]

(ii) Explain why substance P cannot conduct electricity in solid but can conduct electricity molten state.

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

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

[2 marks]

(c) (i) What is the physical state of R and T at room temperature ?

R : ............................................

T : ......................................

[2 marks]

(ii) Draw the arrangement of particles in substance T at room temperature .

[ 2 marks ] (iii) Explain why the melting and boiling points of substance R and T is low ?

.

[ 2 marks ]

4 The diagram 4 shows the electron arrangement of compound J. Compound J formed from reaction between element X and element Y

__

2 +

__

Y Y

X

Y

Diagram 4(a) How are Y ion and X ion formed from their respective atoms?

Y ion: ..

X ion :

[ 2 marks]

(b) (i)Write the formula for compound J

........................................................................................................................ [1 mark]

(ii) Name type of bond in compound J

........................................................................................................................ [1 mark]

(iii) Write the chemical equation for the reaction between element X and element Y to form compound J.

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

[1 mark]

(c)(i) Write the electron arrangement for atom of element X and Y

X :.

Y : ..

[2 marks]

(ii) Between atom of element X and Y, which one has a smaller size. .........................................................................................................................................

[1 mark](iii)Explain your answer in (b) (ii)

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

[3 marks]

(d) Y can react with carbon to form a compound. Draw the electron arrangement for the compound formed.[Given that proton number for carbon is 6][2 marks]

5In an experiment to determine the empirical formula of an oxide of copper , the combustion tube with the porcelain dish are weighed. Oxide of copper is added into the porcelain dish and the tube is weighed again. The oxide of copper is heated strongly. After the set of apparatus cools down to room temperature the combustion tube with its content is weighed again.

The following data is obtained.

Mass of combustion tube + porcelain dish

=19.60 g

Mass of combustion tube + porcelain dish + oxide of copper =25.68 g

Mass of combustion tube +porcelain dish + copper

=24.46 g

(a) What is meant by empirical formula?

[1 mark]

(b) Draw a labeled diagram of the set-up of the apparatus for the experiment.

[2 marks](c) Calculate the empirical formula of the oxide of copper.

[Given that the relative atomic mass of O=16 , Cu=64] [3 marks]

(d) Write the chemical equation for the reaction in the experiment.

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

[1 mark]

(e) Before oxide of copper is heated, hydrogen gas is allowed to pass through the apparatus until all the air in the combustion tube is completely removed.

Describe the steps that should be taken to ensure that all air in the combustion tube has been removed.

[3 marks]

(f) (i) Can the empirical formula of magnesium oxide be determined using the same method as above? Explain your answer.

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

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

[2 marks] (ii) Draw a labeled diagram of the set-up of the apparatus for the experiment

[2 marks]6.Diagram 6 shows shows the chemical symbols which represent elements R, S and T.

R S T

Diagram 6

(a) (i) Write the electron arrangement of atom T

[ 1 mark]

(ii) State the period and the group for element T in the Periodic Table.

Period : ...................................................

Group : ...........................................................

[2 marks]

(b)Atoms of R and S can react to form a compound.

(i) Name the type of bond in the compound formed between atoms R and S.

[1 mark]

(ii) State one physical property of the compound formed in b(i)

..

[1 mark](c) (i) Atom of R and T can also react to form compound. Draw the electron arrangement for the

compound formed.

[2 marks]

(ii) Name the force that exist between particles in the compound formed .

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

[ 1 mark]

(iii) The melting point of the compound formed is 801 C and its boiling points is 1413 C. What is te state of matter for this compound at 1000 C.

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

[ 1 mark]

(d) Arrange R, S and T according to the increase the atomic size

[1 mark]7Lactic acid is an acid produced in milk by bacteria that causes the milk to taste sour. Table 7 shows the percentage of composition by mass of each element in lactic acid.

ElementPercentage

Carbon40.00

Hydrogen 6.67

Oxygen53.33

TABLE 7

(a) Based on the information above, calculate the empirical formula of lactic acid.

Given that the relative atomic mass of H = 1 ; C = 12 ; O = 16

[3 marks]

(b) Relative molecular mass of lactic acid is 90. Determine the molecular formula of lactic acid.

[2 marks]

(c) Calculate the number of hydrogen atom in 1 mol of lactic acid?

Given that Avogadro number ,NA = 6.02 10 23 mol-1

[2 mark]

(d) Calculate the number of moles of 4.5 g lactic acid.

Given that the relative atomic mass of H = 1 ; C = 12 ; O = 16

[1 mark]

(e) Vinegar or ethanoic acid has a similar empirical formula with lactic acid.

(i)Given that three molecules of ethanoic acid have the same mass as two molecules of lactic acid. What is the relative molecular mass of ethanoic acid?

[1 mark]

(ii) Determine the molecular formula of ethanoic acid.

[2 marks]

8Table 8 shows formula of four ions.

Name of ionsSilver ion Zinc ion Nitrate ion Chloride ion

Formula of ionsAg+Zn2+NO3-Cl-

TABLE 8

(a) Write the formula for each compound below :

(i)Silver nitrate............................................................................................

(ii)

Zinc chloride: .......................................................................................................

(ii) Silver chloride: .......................................................................................................

(iii) Zinc nitrate: .......................................................................................................

[4 marks]

(b) When silver nitrate solution is added to zinc chloride solution, white precipitate, silver chloride and zinc nitrate solution are formed.

(i)Identify the reactants and products of the reaction.

Reactants : .......................................................................................................................

Products : .......................................................................................................................

[2 marks]

(ii)

Write the chemical equation for the reaction occurs in (b).

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

[1 mark]

(c) The following equation shows the decomposition of silver nitrate by heat.

2AgNO3

2Ag+ 2NO2+ O2 If 85.0 g of silver nitrate is heated completely, calculate :

(i)the mass of silver formed.

Given that the relative atomic mass of N =14; O = 16; Ag =108

[3 marks]

(ii)the volume of oxygen gas formed at room conditions.

Given that the Molar volume : 24 dm3 at room conditions

[2 marks]

ESSAY SECTION B

9 (a) Diagram 9 shows the models of atoms which were developed by Ernest Rutherford and Neils Bohr

and modern atomic model.

Electron moves outside the

nucleus

Nucleus contains protons

Rutherfords model Bohrs model

DIAGRAM 9

(i) Describe th atomic structure of the Bohrs model [4 marks]

(ii) What is the difference in the position of electrons between the Rutherfords model and Bohrs

model

[2 marks]

(iii) Draw the electron arrangement of an atom that consist of 13 electrons using the modern atomic

model [2 marks]

(b) Chlorine has two isotopes which are chlorine-35 and chlorine-37.The proton number of chlorine is 17.

X

(i) Write the symbol for one of the isotope of chlorine in the form of A

Z [3 marks]

(ii) Compare the number of sub atomic particles in these two isotopes

[4 marks]

(c) Describe fully the atomic structure for chlorine isotope that you have stated in 1(b)(i)

[5 marks]

ESSAY SECTION C

10 (a)

Explain the above statement.

Given that relative molecular mass of carbon dioxide = 44 g mol 1,

relative molecular mass of oxygen = 2 g mol 1

[3 marks]

(b)(i)What is meant by empirical formula?

[ 1 mark](ii) Describe an experiment in the laboratory to determine the empirical formula of magnesium oxide. Your answer should consist of the following.

Procedures of the experiment

Calculation involved

Precautions need to be taken

Given that relative atomic mass of Mg = 24, O = 16

[13 marks]

(c)Magnesium can reduced copper oxide to copper.Explain why the empirical formula of the copper oxide cannot be determined by heating the mixture of copper oxide and magnesium powder.

[ 3 marks]11 Table 11 shows the proton number of atoms P, Q and R.ElementPQR

Proton number81217

TABLE 11(a) Based on electron arrangement, explain the formation of chemical bond between

(i) element P and element P

[5 marks ]

(ii) element Q and element R

[7 marks ]

(b) Gas P reacts with element Q to produce a white solid.

(iii) Write a chemical equation for the reaction between gas P and element Q.

(ii) State three physical properties of the white solid. [ 4 marks] ]

(c) What is the position of elelment Q in the Periodic Table of the elements? Explain how do you obtain your answer.

[ 4 marks ]

PAPER 312. The diagram below shows the apparatus set-up for the experiment to determine the freezing point of substance X.

The diagram below shows the thermometer reading for the cooling of substance X at certain time intervals.

(a) Record the thermometer readings shown in the diagram above by completing the table below. time/minute01234567

Temperature/ oC

[3 marks]

(b) Draw the graph of temperature against time on the graph paper provided.

[3 marks](c) Based on the graph in (b),

(i) State the change in temperature of substance X for the whole experiment.

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

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

........................................................................................................................... [3 marks]

(ii) State the inference for your answer in (c) (i) .

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

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

[3 marks]

(d) What is the freezing point of substance X? Show and label it on the graph how you obtained the answer.

............. [3 marks]

(e) Based on this experiment, what is meant by freezing point?

...

... [3 marks]

(f) If substance X is heated from room temperature until 100oC, what is the temperature when substance X starts to melt? Explain your answer.

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

[3 marks]

13

An experiment is carried out to investigate the statement above.The table below shows the apparatus set up and the observations for the experiment to determine the reactivity of the Group 1 elements based on their reactions with water.

Apparatus set-upObservation towards the metal

Lithium moves slowly on the surface of the water with a hiss sound.

Potassium moves vigorously and randomly on the surface of the water with a hiss sound.

Sodium moves quickly and randomly on the surface of the water with a hiss sound.

(a) State the variables that are involved in the experiment.

Name of variablesAction to be taken

(i) Manipulated variable:

..

..

(i) The way to manipulate variable:

..

...

(ii) Responding variable:

(ii) What to observe in the responding variable:

..

..

(iii) Controlled variable:

..

..

(iii) The way to maintain the controlled variable:

[6 marks]

(b)State one hypothesis for the experiment.

[3 marks]

(c)Based on the observations in the figure above, arrange lithium, potassium and sodium in the descending order of reactivity of metals towards water.

Descending order of reactivity of metals towards water.

[3 markah]

(d)Solution X was produced from the reaction of sodium with water. Classify the ions that exist in solution X into positive ions and negative ions.

Positive Ions Negative Ions

[3 marks]14

Plan an experiment in the laboratory to investigate the reactivity of lithium, sodium and potassium with water and describe the effect of the solution produced towards a red litmus paper. The planning of your experiment must consist of the following:

(a) Aim of experiment (b) Statement of the hypothesis

(c) All the variables

(d) List of substances and apparatus

(e) Procedure of the experiment

(f) Tabulation of data

[17 marks]

Sample Answer

Section A1(a)

[Functional diagram ][ Labeled]

1

1

(b) (i)80 oC1

(ii)PQ : solid

RS : liquid1

1

(iii)The energy is absorbed to overcome the forces of attraction between the particles11

(iv)The particles move faster1

(c)

[The shape of the graph is correct and 80 0C on graph]

[ Both axis are labeled with unit ]11

(d)naphthalene1

11

2(a)2.8.8

1

(b)(i)Z

1

(ii) Achieve octet electron arrangement // achieve 8

electron in the outermost shell // 8 valence electron

1

(c)(i)V

1

(ii)The atomic size of V is smaller than the atomic size of Y

1

The attraction between the nucleus and the outermost occupied shell is stronger in an atom V than an atom Y

1

It is easier for atom V to receive electron

1

(d)(i) High melting / boiling point// dissolve in water// do not dissolve in

organic solvents // conduct electricity in aqueous solution or molten state

1

(ii)

Functional diagram and heating is shown

1

Y/Chlorine gas and iron labeled

1

103 (a)Q1

3(b)(i)Ion 1

3(b)(ii)solid state : Ions are not freely moving// ions are in a fixed position.

molten state : Ion can move freely1

1

3(c)(i)R : Gas

T : Liquid1

3(c)(ii)

2

3(c)(iii) Van der waal/intermolecular forces are weak

Small amount of heat is required to overcome it1

1

Total10

4

(a)Atom Y receive one electron

Atom X receive two electron1

1

(b)(i)X2Y1

(ii)Ionic bond1

(iii)4X + Y2 2X2Y1

(c)(i)X : 2.8.2

Y : 2.8.71

1

(ii)Y 1

(ii) Atom X and atom Y have the same number of shells occupy with electrons

The number of proton in the nucleus of atom Y is more than X

Nulcei attraction to the electrons in the shells of atom Y is stronger than X1

1

1

(d) Electron arrangement all atoms are correct

One carbon atom share four pairs of electrons with 4 Y atoms1

1

Total12

5(a)Formula that shows the simplest ratio of the number of atoms

for each element in the compound.

1

(b)

Functional diagram an heating is shown

1

Dry hydrogen gas and oxide of copper are labelled

1

(c)

Cu

O

24.46 19.60 / 4.86

25.68 24.46 / 1.22

1

4.86/ 0.076 1.22 / 0.076

1

64

16

CuO

1

(d)CuO + H2 ( Cu + H2O

1

(e)Collect the gas in a test tube

1

Put lighted wooden splinter at the mouth of the test tube

1

No pop sound

1

(f) (i) No

1

Magnesium more reactive than hydrogen //

Hydrogen less reactive than magnesium // hydrogen below

magnesium in reactivity series.

1

(ii)

Functional diagram and heating is shown

1

Magnesium is labeled

1

146(a)i2.8.1 // 2,8,1

1

ii3

11

1

(b)iCovalent bond

1

iiLow melting point and boiling point//insoluble/does not dissolve in water//soluble/dissolve in organic solvent//does not conduct electricity in any state

Choose one

1

(c)(i)Number of electrons for ion T and ion R are correct

Charge of ions and ratio of ion T to ion R are correct1

1

(ii)Elecrostatic1

(iii)Liquid / molten state1

(d)S, R,T1

Total10

7(a)Element

C

H

O

Number of moles (mol)

= 3.33

= 6.67

= 3.33

Ratio of moles

1

2

1

1

1

The empirical formula of the compound is CH2O1

(b)n [ 12 + 2(1) + 16 ]= 90

n=

= 3Molecular formula of lactic acid is C3H6O31

1

(c)One molecule of lactic acid contains 6 hydrogen atoms//

1 mol of lactic acid contains 6 mol of hydrogen atoms

1 mol of lactic acid contains 6 6 .02 10 23 hydrogen atoms1

1

(d)The number of mole of lactic acid=

= 0.05 mol1

(e)3 Mr of ethanoic acid= 2 Mr of lactic acid

Mr of ethanoic acid=

= 601

(f)n (30)= 60

n= 2

Molecular formula of ethanoic acid is C2H4O2 / CH3COOH1

1

11

8(a) (i)AgNO31

(ii)ZnCl21

(iii)AgCl1

(iv)Zn(NO3)21

(b) (i)Silver nitrate and zinc chloride1

Silver chloride and zinc nitrate1

(ii)2AgNO3+ ZnCl2 2AgCl +Zn(NO3)21

(c) (i)Number of moles of AgNO3 =

= 0.5 mol1

2 moles of AgNO3 produce 2 moles of Ag

0.5 mole of AgNO3 produce 0.5 mole of Ag1

Mass of Ag= 0.5 108

= 54 g1

(ii)2 moles of AgNO3 produces 1 mole of O20.5 mole of AgNO3 produces 0.25 mole of O21

Volume of O2= 0.25 24

= 6 dm31

10

SECTION B9 (a) (i) 1. Atom consist proton and electron

1 2. Electrons in the shell

1 3. Protons are in the nucleus

1

4. The nucleus in the middle of the atom

1

(ii) 1. Rutherfords model: Electrons outside the nucleus

1 2. Bohrs model: Electrons in the shell

1

(iii)

1. Atom with nucleus and the number of shells is 3

1 2. Correct number of electrons: 2.8.3

1

(b) (i) 35 37

Cl Cl

17 17

1. Symbol of an element

1

2. Nucleon number

13. Proton number

1

(ii) 1. Chlorine-35 and chlorine-37 have 17 protons// The electron arrangements of chlorine-35 and chlorine- 37 are 2.8.7

1

2.The number of neutron in chlorine-35 and chlorine- 37 are 18 and 20 respectively//

The nucleon number of chlorine-35 and chlorine- 37 are 35 and 37 respectively 1

(c) 1. Nucleus is at the centre of the atom

2. Nucleus contains 17 protons, which are positively charged particles

3. The number of neutrons are 18/20 which are neutral particles

4. The nucleon number is 35/37

5. Electron cloud consist of 17 electrons

6. Electron which is negatively charged particles move around the

nucleus// Electron is located outside the nucleus/in the shell

7. Electron arrangement is 2.8.7// The number of shells field with electrons are 3 any 5

Total: 20

SECTION C10(a)Number of mole of carbon dioxide = = 0.05 mol

1

Number of mole of hydrogen = = 1.1 mol

1

The number of mole of carbon dioxide is smaller; therefore, its volume is smaller than the volume of hydrogen

1

(b)(i)The empirical formula of a compound is the formula that shows the simplest

whole number ratio of atoms of each element present in the compound.

1

(ii)[Material and apparatus ]

[Magnesium ribbon, sand paper, crucible with lid, tongs, Bunsen burner, tripod stand, pipe-clay triangle and balamce.] or [diagram]

2

[Procedure]

A crucible and its lid is weighed and its weight is recorded.

1

A 10 cm length of magnesium ribbon is coiled loosely and is placed in the crucible.1

The crucible with its lid and content are weighed again and the weight is recorded .1

The crucible is heated strongly without its lid.

1

When the magnesium starts to burn, the crucible is covered with its lid.

Using a pair of tongs, the lid is lifted at intervals.

1

When the burning is completed, the lid is removed and the crucible is heated strongly for 2 minutes.

1

The rucible is allowed to cool to room temperature.

1

The crucible and its lid and content are weighed again and its weight is recorded.1

max 5

[Precautions taken]

The magnesium ribbon is cleaned with sand paper to remove the layer of magnesium oxide on the surface.

The crucible must cover with its lid to prevent the white fumes of magnesium oxide of escaping.

The processes of heating, cooling and weighing are repeated untila constant mass is obtained.

[any two of the above]2

[ Results ]

Crucible + lid

= a g

Crucible + lid + magnesium

= b g

Crucible + lid + magnesium oxide = c g

1

[ Calculation ]

ElementMagnesiumOxygen

Mass(g)b-ac-b

Number of moles of atomsb-a/24c-b/16

Simplest ratio of molesXy

2

Empirical formula = MgxOy

1

(c)1Unable to make sure that all the magnesium is oxidised . 1

2The products (Cu and MgO) cannot be separated.

1

3The mass of copper and oxygen cannot be determined.

1

2011(a)(i) 1.Two atoms of P combine through covalent bond.

1

2. Each atom of P needs two more electrons to achieve octet electron arrangement.

3.Each atom of P contributes two electrons to each other for sharing. 1

4. Two atoms of P share two pairs of electrons.

1

5. A double covalent bond is formed.

P

P

2

(ii)1. Atom Q and atom R combine through ionic bond.

1

2. To achieve octet electron arrangement,

1

3. atom Q with 6 valence electrons loses two electrons to form Q2+ ion 1

4. Two atom R, each atom with 7 valence electrons gains one electron to form R- ion.

1

5. Q2+ ion and R- ion are attracted to each other by strong electrostatic force.1

_

2+

_

R

Q

R

2

(b)(i) 2Q + P2 2QP

1

(ii) 1.Have high melting point

1

2. Usually soluble in water

1

3. Conduct electricity in the molten state or aqueous solution. 1

1. Element Q is located in Group 2

1

2. because it has two valence electrons

1

3. Element Q is located in Period 3

1

4. because it has three shells occupied with electrons

1

20PAPER 3 QuestionRubric

12 (a)Able to record all the readings correctly to 1 decimal place.

Time (minute)

0

1

2

3

4

5

6

7

Temperature (oC)

95.0

89.0

84.5

83.0

83.0

83.0

77.0

70.0

12 (b)Able to draw the graph with the following elements::

X-axis is labeled(minute) and y-axis temperature(oC) with consistent scales

Size of the graph is at least half the page of the graph paper.

All the points are plotted correctly

Curve of the graph is correct and smooth

QuestionRubric

12 (c) (i)Able to explain the change of temperature with time from the graph.

Suggested answer:

In the first 3 minutes, the temperature of substance X will decrease from 95oC to 83oC.

Constant temperature at 83 oC for 3 minutes.

The temperature decreases again after 83 oC

12 (c) (ii)Able to make the correct inference.

Suggested answer:

Temperature decreases because heat is released to the surrounding.

Temperature is contant because heat released to the surrounding is balanced by the heat released when bonds are formed.

The freezing process is at 83 oC // solid and liquid X exist together

12 (d) Able to state the freezing point accurately based on the graph with the correct unit. Dotted line is shown on the graph. Labeling the freezing point at temperature axis.

12 (e)Able to give the meaning of freezing point accurrately.

Suggested answer:

Freezing point is the constant temperature at 83oC even though substance X is let to cool to room remperature.

12 (f)Able to predict the melting point of substance X accurately with unit and with correct reasons.

Suggested answer :83.0 oC

Value of melting point substance X is the same as its freezing point.

QuestionRubricRubric

13 (a)Able to predict the manipulated variable, the responding variable and the constant variable completely.Suggested answer: Manipulated variable: metals of Group 1 elements // sodium, lithium, potassium.

Responding variable: the reactivity of the reaction with water // the speed of movement on the water surface

Constant variable: size/mass of metals. Volume of water

Able to state how to control the manipulated variables correctly

Suggested answer: Repeat the experiment by using the metals of sodium, lithium and potassium

Able to state correctly the way to control the manipulated variable

Suggested answer:

To observe how fast the metals move on the surface of water.Able to use the metal granules with the same size

Suggested answer :

Use the metal granules with the same size.

13 (b)Able to state the relationship between the manipulated variable and the responding variable correctly..

Suggested answer: The reactivity of Group 1 elements increases going down the group.

13 (c)Able to arrange correctly the reactivity series of the metals according to descending order.

Answer: potassium, sodium, lithium

13 (d)Able to classify the ions correctly.

[to name or write all the formula of the ions correctly at the cations and anions group.]

Answer: positive ion/ cation : sodium ion/ Na+, hydrogen ion/ H+ Negative ion/anion : hydroxide ion/ OH-

QuestionRubricScore

14(a)[Able to state the aim of experiment accurately]

To compare the reactivity of lithium, sodium and potassium based on the reaction with water and describing the effect of the solution towards the red litmus paper.3

14(b) Hypothesis

Metals of lithium, sodium and potassium show different rate of reactivity with water and the solution formed turns red litmus paper to blue.

14(c)Variables

a) Manipulated variable :type of metals

b) Responding variable : reactivity of reaction

c) Constant variable : water and temperature 3 x1

2x1

1x1

14(d)[Able to list the correct and complete substances and apparatus.]

Substances and Apparatus

Lithium, sodium and potassium metals with water, basin, knife, forceps, blue litmus paper and white tile.3

14(e)[Able to give all the procedures correctly, steps 1 - 7]

1. Lithium metal is cut into a small piece

2. The paraffin oil on the surface of the metal is wiped with the filter.

3. A basin is filled with water.

4. Lithium metal is put on the surface of the water with a pair of forceps.

5. Reactivity of the reaction is observed and recorded.

6. The experiment is repeated with sodium and potassium metals.3

14(f)[Able to show the accurate tabulation of data with correct title.]

Metals

ObservationsLithiumSodiumPotassium

3

Temperature / 0C

Time/s

80

30

360

P

Q

R

S

12

23

35

17

11

6

Nucleus contains

protons

Shell

Modern atomic structure

Electron

The volume of 2.2 g of carbon dioxide gas is less than the volume of 2.2 g of hydrogen at the same temperature and pressure.

thermometer

Substance X

Volumetric flask

90

95

85

0 Minute

1st minute

2nd Minute

3rd minute

85

90

80

85

90

80

85

90

80

85

90

85

90

80

75

80

70

70

75

65

4th minute

5th minute

6th minute

7th Minute

Elements in Group 1 of the Periodic Table of Elements can be arranged based on the reactivity of the elements with water.

Lithium

water

))

)))

Potassium

)) ) )

water

water

sodium

)) )

When lithium metal is put in water, it moves very slowly on the surface of the water. When sodium metal is put in water, it moves quite fast and produces hiss sound. When potassium metal is put in water, it moves very fast and produces small explosions. Metal

Water

Heat

Substance X

water

Thermometer

Boiling tube

Temperature / 0C

Time/s

80

Y/Chlorine gas

Iron

Heat

Oxide of copper

Dry hydrogen gas

Heat

Magnesium

Heat

T

-

+

R

Graph of temperature against time

Temperature/oC

Melting point

Time/minute

EMBED PBrush

PAGE 21Set 1

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