chem juj k1+k2+k3 (skema jawapan) [set 1]
TRANSCRIPT
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 1
SKEMA JAWAPAN KERTAS 1
JUJ KIMIA SET 1 – 2017
1 A 11 D 21 C 31 D 41 A
2 D 12 A 22 B 32 B 42 A
3 B 13 C 23 B 33 B 43 D
4 B 14 A 24 B 34 C 44 D
5 C 15 A 25 C 35 B 45 A
6 D 16 C 26 A 36 B 46 D
7 A 17 C 27 B 37 A 47 B
8 D 18 A 28 B 38 B 48 B
9 C 19 C 29 D 39 A 49 C
10 A 20 C 30 B 40 B 50 B
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 2
MARKING SCHEME PAPER 2 SET 1 JUJ CHEMISTRY 2017
Question No. Mark Scheme Sub
Mark ΣMark
1 (a) Horizontal rows of elements in the Periodic Table of
elements
1 1
(b) Atoms have three shells filled with electron 1 1
(c) 2.8.5 1 1
(d) (i) 1. Atom has achieved stable octet electron arrangement
// atom has eight valence electron
2. Atom does not receive, donate or share electron with
other atom
1
1
2
(ii) Aluminium / Al 1 1
(iii) Al2O3 1 1
(e)
pH value pH 2 pH 13
Oxide of element SO2 Na2O
1 + 1
2
TOTAL 9
Question No. Mark Scheme Sub
Mark ΣMark
2 (a) (i) Oil // Fats 1 1
(ii) Ester 1 1
(iii) Saponification 1 1
(b) (i) A: Soap
B: Detergent
1
1
2
(ii) Magnesium ion/ Mg2+
// Calcium ion/ Ca2+
1 1
(c) (i) Ethene 1 1
(ii)
1 1
(iii) - It is non biodegradable//
- Produce poisonous/toxic gas when burn//
- Improper disposal, clog the drain//
- Improper disposal, place for mosquito breeding.
[Any one]
1 1
TOTAL 9
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 3
Question No. Mark Scheme Sub
Mark ΣMark
3 (a) (i) NO2 1 1
(ii) 1. Correct number of atoms and nucleus is shown.
2. Correct number of electron in each shell and correct
number of electron shared.
1
1
2
(iii) molecule 1 1
(iv) 1. Correct formula of reactants and products
2. Balanced equation
N2 + 2O2 2NO2
1
1
2
(b) (i) Ionic bond 1 1
(ii) 1. Magnesium atom donates two electrons to
form Mg2+
2. Oxygen atom receive two electrons to form O2-
1
1
2
(iii) High melting/ boiling point //
Can conduct electricity in molten/ aqueous solution//
Soluble in water//Insoluble in organic solvent
1
1
TOTAL 10
Question No. Mark Scheme Sub
Mark ΣMark
4 (a) Heat change when one mol of metal is displace from its
salt solution by a more electropositive metal.
1 1
(b) To reduce heat loss to the surrounding. 1 1
(c)
Temperature increase // Brown solid deposited// Blue
colour of CuSO4 become paler
1 1
(d)
(i) H = 100(4.2)(10) J // 4200 J // 4.2 kJ 1 1
(ii) 1. number of mole
2. Heat of displacement with correct unit and negative
sign
1
1+1
3
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 4
Question No. Mark Scheme Sub
Mark ΣMark
n = // 0.05
H = - J mol-1
// 84000 Jmol-1
// 84 kJmol-1
(e) Exothermic reaction 1 1
(f)
1. Magnesium // [Any metal higher place than copper in
the electrochemical series]
2. Located higher than copper in the electrochemical
series // More electropositive than copper
1
1
2
TOTAL 10
Question No. Mark Scheme Sub
Mark ΣMark
5 (a) (i) Double decomposition reaction 1 1
(ii) Lead(II) nitrate / Pb(NO3)2
Sodium carbonate / Na2CO3 // Potassium carbonate/
K2CO3// Ammonium carbonate/ (NH4)2CO3
1
1
2
(iii) 1. Correct formula of reactants and products
2. Balanced equation
Pb(NO3)2 + Na2CO3 Pb CO3 + 2NaNO3
1
1
2
(iv) White 1 1
(b)
(i) Sodium carbonate / Na2CO3 // Potassium carbonate /
K2CO3 // Ammonium carbonate / (NH4)2CO3
1
1
(ii) Cu2+
+ CO32-
CuCO3 1 1
(iii) 1. Pour the treated waste water into a test tube.
2. Add sodium hyroxide solution into the test tube.
3. Blue precipitate does not formed.
OR
1. Pour the treated waste water into a test tube.
2. Add ammonia aqueous into the test tube.
3. No change.
1
1
1
3
TOTAL 11
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 5
Question No. Mark Scheme Sub
Mark ΣMark
6 (a) (i) K+, Cl
-, H
+, OH
- 1 1
(ii) Bubble gas released // colourless gas released 1 1
(iii) R: Chlorine
T: Oxygen
1
1
2
(b) (i) Copper(II) sulphate / CuSO4 // Silver nitrate /AgNO3 //
Sodium chloride / NaCl //
[Any suitable electrolyte]
1
1
(ii) V, W, Z, Y, X 1 1
(iii) 1. V and X
2. 2.80 V
1
1
2
(iv) 1. Silver
2. Silver is located below copper in
electrochemical series// Silver is less
electropositive than copper
1
1
2
(c) Electrical energy to chemical energy 1 1
TOTAL 11
Question No. Mark Scheme Sub
Mark ΣMark
7 (a) (i) 1. Solvent L : Propanon // methylbenzene // [any
suitable organic solvent]
2. Solvent M : Water
Beaker A Beaker B
3 No gas bubbles release
// No change
Gas bubbles release //
colourless gas X
collected in the syringe
4 HCl does not ionise // no
H+ ion // HCl exist as
molecule
HCl ionise // present of
H+ ion
5 No reaction Reaction occur
6 Blue litmus paper does
not change colour
Blue colour litmus paper
change to red
1
1
1
1
1
1
6
(ii) 3. Correct formula of reactants and products
4. Balanced equation
5. Number of mole
6. Mole ratio
7. Molar mass of CaCO3
8. Mass with correct unit
1
1
1
1
1
1
6
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 6
Question No. Mark Scheme Sub
Mark ΣMark
CaCO3 + 2HCl CaCl2 + H2O + CO2
Moles gas = // 0.001
1 moles gas X produced from 1 moles CaCO3 //
0.001 moles gas X produced from 0.001 moles CaCO3
Molar mass CaCO3 = 40 + 12 + 3(16) // 100
Mass CaCO3 = 0.001 x 100 g // 0.1g
(b) (i) 1. HX : HCl // HNO3
2. H2Y: H2SO4
3. HZ : CH3COOH
Compare pH value of acid H2Y and acid HX.
H2Y is diprotic acid //
1 mole of H2Y ionise in
water produce 2 moles
of H+ ion
HX is monoprotic acid //
1 mole of HX ionise in
water produce 1 moles
of H+ ion
4. Concentration of H+ ion in H2Y is higher than in HX
5. The higher the concentration of H+ ion the lower the
pH value
1
1
1
1
1
1
(ii) Compare pH value of acid HZ and acid HX.
HZ is a weak acid // HZ
ionise partially in water
produce lower
concentration of H+ ion
HX is a strong acid // HX
ionise completely in
water produce higher
concentration of H+ ion
The lower the concentration of H+ ion the higher the
pH value
1
1
8
TOTAL 20
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 7
Question No. Mark Scheme Sub
Mark ΣMark
8 (a) 1. Fe: +3
2. Mg: +2
3. Fe2O3: Iron(III) oxide
4. MgO : Magnesium oxide
5. Iron has roman numeral because it has more
than one oxidation number
6.Magnesium has no roman numeral because it
has only one oxidation number
1
1
1
1
1
1
6
(b) 1. Glucose undergoes oxidation
2. by losing hydrogen
3. Oxygen undergoes reduction
4. by gaining hydrogen
1
1
1
1
4
(c) 1. Reaction I : +3 +2
2. Reaction II: +2 0
3. Reaction III: +2 +3
4. Metal X: Magnesium//Zinc//Aluminium
5. Substance Y: Magnesium//Zinc//Aluminium
6. Substance Z: Bromine
7. Reaction II:
1. Correct formula of reactants and products
2. Balanced equation
Fe2+
+ Zn Fe + Zn2+
8. Reaction III:
1. Correct formula of reactants and products
2. Balanced equation
2 Fe2+
+ Br2 2 Fe3+
+ 2Br-
1
1
1
1
1
1
1
1
1
1
10
TOTAL 20
Question No. Mark Scheme Sub
Mark ΣMark
9 (a) 1. Temperature
2. Time taken for clothes to dry in situation II is shorter
compare to situation I // Clothes in situation II dry
faster than in situation I.
3. Temperature in situation II is higher than situation I
4. Kinetic energy of particles in situation II is higher
than situation I
5. The rate of water particles evaporate in situation II is
higher than situation I
6. The higher the temperature the higher the rate of
reaction
1
1
1
1
1
1
6
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 8
Question No. Mark Scheme Sub
Mark ΣMark
(b) (i) 1. Correct formula of reactants and products
2. Balanced equation
3. Rate of reaction set II with correct unit.
4. Rate of reaction set III with correct unit.
Mg + 2HNO3 Mg(NO3)2 + H2
Rate of reaction set II = gs-1
// 0.003 gs-1
Rate of reaction set III = gs-1
// 0.005 gs-1
1
1
1
1
4
(ii) Time taken for magnesium dissolved in set II is
shorter than set I
1. Concentration of nitric acid in set II is higher than
set I
2. Number of particles / H+ ion perunit volume is
higher
3. Frequency of collision between Mg and H+ ion is
higher
4. Frequency of effective collision is higher
5. Rate of reaction in set II is higher.
Time taken for Magnesium dissolved in set III is
shorter than set II
6. Temperature in set III is higher than set II
7. The kinetic energy of particles is higher
8. Frequency of collision between Mg and H+ ion is
higher
9. Frequency of effective collision is higher
10. Rate of reaction in set III is higher.
1
1
1
1
1
1
1
1
1
1
10
TOTAL 20
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 9
Question No. Mark Scheme Sub
Mark ΣMark
10 (a) 1. Process I : Dehydration
2. Process II : Esterification
3. Homologous series compound P : Alcohol
4. Compound P : Hydroxyl group / -OH
5. Compound Q : Double covalent bond between carbon
atoms / C=C
6. Compound R : Carboxyl group / -COOH
1
1
1
1
1
1
6
(b) 1. Correct formula of reactants and products
2. Balanced equation
3. Mole ratio
4. Mass with correct unit
C2H5OH C2H4 + H2O
1 moles C2H4 produced from 1 moles C2H5OH //
0.0005 moles C2H4 produced from 0.0005 moles C2H5OH
Mass C2H5OH = 0.0005 x 46 g // 0.023 g
1
1
1
1
4
(c) 1. Compound P : Ethanol
2. Compound R : Butanoic acid
3. Measure 2 cm3 of glacial ethanoic acid and pour into
a boiling tube
4. Add 2 cm3 of absolute ethanol into the boiling tube
5. Add few drops of concentrated sulphuric acid and
shake
6. Heat the mixture
7. Pour the mixture into a beaker of water
8. Pineapple smell // sweet fruity smell
9. C2H5OH + C3H7COOH C3H7COO C2H5 + H2O
10.
1
1
1
1
1
1
1
1
1
1
10
TOTAL 20
END OF MARKING SCHEME PAPER 2
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 10
PERATURAN PEMARKAHAN KIMIA KERTAS 3 JUJ 2017 SET 1
Soalan Pemarkahan Markah
1(a)
Able to record all reading accurately to one decimal point and with
unit.
Sample answer:
Initial temperature : 60.0 oC
Temperature at 1 min : 67.0 oC
Temperature at 2 min : 73.0 oC
Temperature at 3 min : 80.0 oC
Temperature at 4 min : 80.0 oC
Temperature at 5 min : 80.0 oC
Temperature at 6 min : 87.0 oC
Temperature at 7 min : 95.0 oC
3
Able to record all readings correctly without decimal point//
Able to record 5-6 readings correctly
2
Able to record 3-4 readings correctly 1
No response or wrong response 0
Soalan Pemarkahan Markah
1(b)
Able to plot a graph that contains the following information.
- Axes labeled with units
- All the 8 points transferred correctly
- A smooth curve is drawn
- Uniform scale
Sample answer:
Temperature/oC
Time/min
3
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 11
Soalan Pemarkahan Markah
1(c)
Able to state the melting point with 1 decimal place and show on the
graph correctly
Sample answer:
Temperature/oC
80.0
Time/min
3
Soalan Pemarkahan Markah
Able to give an idea to plot a graph
Sample answer:
1
No response or wrong response or empty table 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 12
Soalan Pemarkahan Markah
1(c)
Able to state the melting point correctly without decimal place but with
correct unit without showing on the graph//Able to state the melting
point on the curve
Sample answer:
Melting point of naphthalene: 80 oC //
Temperature, oC
Melting point
Time/min
2
1(c)
Able to state the melting point less accurately without unit and without
decimal place // Able to show the melting point incorrectly;
Sample answer:
Melting point of naphthalene : 80 //
Temperature/oC
Melting point
Time/min
1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 13
Soalan Pemarkahan Markah
1(d)
Able to explain correctly according to 3 information :
- Heat energy absorbed
- is used to over come the forces of attraction between the
molecules
Sample answer:
Heat energy absorbed is used to overcome the forces of attraction
between the molecules
3
Able to explain less accurately
Sample answer:
The heat energy is used to overcome the forces of attraction
2
Able to state an idea
Sample answer:
The heat energy is used/absorbed//solid turn to liquid//the heat energy is
used to overcome the forces.
1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 14
Soalan Pemarkahan Markah
1(e)
Able to predict the temperature at the 8th
minutes with unit and decimal
place correctly
Answer:
101.0 0C
3
Able to predict the temperature at the 8th
minutes without unit and
decimal place correctly
Sample answer:
101.0 // 101 0C //101
2
Able to predict the temperature at the 8th
minutes less correctly
Sample answer:
Lebih dari 94. 0C // [102 ≤ X ≤ 105] // [95 ≤ X ≤ 100]
1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 15
Soalan Pemarkahan Markah
1(f)
Able to classify all the compound correctly
Sample answer:
Ionic compound Covalent compound
Potassium bromide
Copper(II) sulphate
Aluminium oxide
Ammonia
Methanol
tetrachloromethane
3
Able to classify any 5 compounds correctly. 2
Able to classify at least 2 compound correctly 1
No response or wrong response 0
Soalan Pemarkahan Markah
2 (a)
Able to state all observations and inferences correctly.
Sample answer:
Experiment Observation Inference
I Bulb does not lights up Cannot conduct electricity//
Covalent compound
II Bulb does not lights up Cannot conduct electricity//
Covalent compound
III Bulb lights up Can conduct electricity//
Ionic compound
6
Able to state at least 5 observations and inference correctly 5
Able to state at least 4 observation and inference correctly 4
Able to state at least 3 observation and inference correctly 3
Able to state at least 2 observation and inference correctly 2
Able to state at least 1 observation and inference correctly 1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 16
Soalan Pemarkahan Markah
2 (b)
Able to state all the variables in this experiment correctly.
Sample answer:
(i) Manipulated variables : Type/different substance/ionic compound
and covalent compound
(ii) Responding variable : electrical conductivity//bulb lights up and
the bulb does not light up
(iii) Constant variable : mass of substance/compound//carbon
electrode
3
Able to state any two variables correctly 2
Able to state any one variable correctly 1
No response or wrong response 0
Soalan Pemarkahan Markah
2 (c)
Able to state the relationship between the manipulated variable and the
responding variable correctly
Sample answer:
Covalent compound cannot conduct electricity/lights up the bulb and
ionic compound can conduct electricity/lights up the bulb
3
Able to state the relationship between the manipulated variable and the
responding variable less correctly
Sample answer:
Covalent compound cannot conduct electricity/lights up the bulb // ionic
compound can conduct electricity/lights up the bulb
2
Able to give an idea of hypothesis
Sample answer:
Conduct electricity/bulb lights up
1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 17
Soalan Pemarkahan Markah
2 (d)
Able to give one operational definition of the experiment correctly with
the following aspects:
i) what you do-dip /immerse (carbon electrode )in electrolyte/PbBr2
ii) what you observe-bulb lights up
Sample answer:
1. when carbon electrode is dipped in electrolyte/lead(II)
bomide /PbBr2
2. Bulb lights up
3
Able to give the operational definition for electrical conductivity for
ionic compound incompletely with any one of the following aspects:
i).what you do
ii).what you observe
Sample answer:
Bulbs lights up/dip carbon electrode in lead(II) bromide/electrolyte
2
Able to give an idea of operational definition for electrical conductivity
for ionic compound
Sample answer:
Carbon electrode is dipped / [electrolyte] is used /molten state
1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 18
Soalan Pemarkahan Markah
3 (a)
Able to state the problem statement with the named of strong acid and
weak acid correctly
Sample answer:
Does the heat of neutralisation between hydrochloric acid/(any strong
acid) and sodium hydroxide solution is higher than the heat of
neutralisation between ethanoic acid(any suitable weak acid) and sodium
hydroxide solution?
3
Able to state the problem statement less correctly
Sample answer:
Does the heat of neutralization between strong acid and weak acid with
strong alkali different ? //To study the heat of neutralization between
strong and weak acid with strong alkali.
2
Able to state an idea about problem statement
Sample answer:
Heat of neutralisation is affected by the strength of acid.
1
No response or wrong response 0
Soalan Pemarkahan Markah
3 (b)
Able to state the relationship between the manipulated variable and the
responding variable and state the direction correctly.
Sample answer:
The reaction between hydrochloric acid/strong acid and sodium
hydroxide will give the higher value of heat of neutralization than the
reaction between ethanoic acid/weak acid with sodium hydroxide.
3
Able to state the relationship between the manipulated variable and the
responding variable without stating the direction/ less accurately
Sample answer:
Different strength of acid react with sodium hydroxide, different value
of heat of neutralisation
2
Able to give an idea of hypothesis
Sample answer:
The strength of acid affect the heat of neutralisation
1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 19
Soalan Pemarkahan Markah
3(d)
Able to list down the materials and apparatus correctly
Sample answer:
Materials : [0.5-2.0mol dm-3
] sodium hydroxide solution,
[0.5-2.0mol dm-3
] hydrochloric acid, [0.5-2.0 mol dm-3
]
ethanoic acid (any suitable strong and weak named acid),
Apparatus : Polystyrene/plastic cup, thermometer, [50-100cm3]
measuring cylinder
3
Able to give the list of the apparatus and materials correctly but not
complete
Sample answer:
Sodium hydroxide solution, hydrochloric acid / ethanoic acid,
Polystyrene/plastic cup, thermometer,
2
Able to give an idea on the list of the apparatus and substances
correctly
Any one materials and any one apparatus
1
No response or wrong response 0
Soalan Pemarkahan Markah
3(c)
Able to state all the variables accurately
Sample answer:
Manipulated variable : Hydrochloric Acid and Ethanoic Acid
(any suitable named strong and weak acid)
//Strong acid and weak acid //X and Y acid
Responding variable : Heat of neutralisation
Fixed variable : Concentration and volume of NaOH
solution//NaOH solution//polystyrene cup //
Concentration and volume of acid solution
3
Able to give any two variables accurately 2
Able to give any one variable accurately 1
No response or wrong response 0
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 20
Soalan Pemarkahan Markah
3(e)
Able to state all the steps of the experiment accurately
Answer:
1. [25-100 cm3] of sodium hydroxide solution is poured into a
polystyrene cup using a measuring cylinder.
2. The initial temperature of sodium hydroxide solution is recorded.
3. [25-100cm3] of hydrochloric acid is measured into another
polystyrene cup.
4. The initial temperature of hydrochloric acid is recorded.
5. Hydrochloric acid is then poured quickly into a cup containing
sodium hydroxide solution.
6. The mixture is stirred using thermometer
7. The highest temperature is recorded.
8. Repeat steps 1 to 6 using ethanoic acid instead of hydrochloric acid.
3
Able to state 5 steps of the experiment
Steps 2, 4, 5, 8
2
Able to state 2 minimum steps correctly
Steps 5, 6/7
1
No response or wrong response 0
Soalan Pemarkahan Markah
3(f)
Able to construct the table that contains the following information
1. Columns and rows
2. Headings in the table
3. With unit
Sample answer:
Pair of acid/alkali
Initial temperature/ oC Highest temperature
of the mixture/o C
Acid Alkali Average
NaOH/HCl
NaOH/CH3COOH
2
SKEMA PRAKTIS BESTARI JUJ KIMIA SET 1 KERTAS 1, 2 & 3
4541 Set 1 © Hak Cipta JUJ Pahang 2017 21
Soalan Pemarkahan Markah
3(f)
Able to construct the table that contains the following information
1. Columns and rows
2. Headings in the table
3. Without unit
//Able to state an idea about the tabulation of data
Tabulation of data has the following elements:
Minimum 2 columns and 2 rows
Sample answer:
Pair of acid/alkali
Initial temperature Highest
temperature of the
mixture
Acid Alkali
//
Sample answer:
Pair of acid/alkali Temperature
1
No response or wrong response 0
PERATURAN PEMARKAHAN TAMAT