science 5 ep tsc/tsc science 201… · science time allowed: 3 hours 3. ... 4. answer all questions...
TRANSCRIPT
1
TONGA SCHOOL CERTIFICATE
2016
SCIENCE
Time Allowed: 3 Hours
YOU MUST HAND THIS BOOKLET TO THE SUPERVISOR AT THE END OF THE
EXAMINATION.
MARKER CODE
STUDENT ENROLMENT NUMBER
QUESTION AND ANSWER BOOKLET
INSTRUCTIONS
1. Answer ALL questions.
2. This paper has ONE COMPULSORY SECTION.
Six Questions worth a total of 70 SKILL LEVEL
3. Write your Student Enrolment Number on the right hand corner and also
on the last page.
4. Answer ALL questions in the space provide in this booklet
5. Use BLUE or BLACK ball point pen. DO NOT write in pencil.
6. If you need more space for any answer, ask the supervisor for extra paper.
7. Check that your paper consists of 19 pages and that page 19 has been
deliberately left blank.
This is a list of formulae that maybe used:
F = ma V = λf W = Fd
V = IR =
P = W/t V =
2 QUESTION 1 WAVE, HEALTH and DISEASE
PART A: WAVE
1. The speaker shown below is producing sound.
a. Label a rarefaction by placing an X on the diagram.
b. Electronic equipment can represent sound waves on a screen.
Screen A shows a soft sound. Draw the pattern on Screen B to
show the same note with a louder sound.
2. The two diagrams below show two waves A and B. Both waves travel
at the same speed.
a. Use a ruler to measure the wavelengths of the two waves A and B
shown above.
Wave A : _______ cm Wave B : _______ cm
b. If the frequency of wave A is 4Hz, calculate the frequency of wave B.
Screen A
A
B
Screen B
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X X X X X
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PART B : HEALTH and DISEASE.
The graph below shows the temperature of a compost heap that was measured
over a month.
a. State the reason for making compost.
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b. Two processes have been occurring inside the compost heap that have
resulted in the rapid rise in temperature during the first week.
Identify these TWO (2) processes.
Process One : ________________________________________________________
Process Two : ________________________________________________________
c. Explain how the processes cause the rise and fall in temperature as
shown by the graph.
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QUESTION 2: NON- METALS, FORCE and ENERGY.
PART A: NON-METALS
1. Study the diagram below that represents the Nitrogen Cycle and answer
the questions that followed.
a. Name bacteria B.
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b. With reference to bacteria A, explain why legumes can grow well
in soil with low level of nitrogen.
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Bacteria A
Bacteria B
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2. THE CONTACT PROCESS.
This is a three stage process which converts liquid sulfur into
concentrated sulfuric acid.
Stage 1: The furnace
In this stage liquid sulfur is burned in a streamed of cleaned dried air to give
sulfur dioxide. This is an exothermic reaction represented by the equation.
S + O2 SO2
a. Describe what exothermic mean?
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Sulfur dioxide gas produced is passed on to Stage 2.
b. Summarize in 2 – 3 sentences what happen in Stage 2.
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c. Name the catalyst used in this stage.
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PART B: FORCE and ENERGY
1. The speed time graph below represents part of the journey of a car.
Use the mass of the car(m = 1200kg) and information from the graph to :
a. Calculate the net force acting on the car in Section A.
b. Describe the motion of the car in Section B to show that the net force
acting on it is zero.
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Speed time graph for a car journey
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QUESTION 3: METAL COMPOUNDS and ELECTRICAL ENERGY.
PART A : METAL COMPOUNDS.
1. Hydrogen peroxide H2O2 is a colorless liquid.
Hydrogen peroxide, decomposes according to the equation below.
Hydrogen peroxide water + oxygen
State the total number of atoms which are bonded in one molecule of
hydrogen peroxide.
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2. The diagram below shows the apparatus which a student used to
measure the rate at which hydrogen peroxide decomposes.
The student measured the time for a known volume of oxygen gas to
collect in the measuring cylinder.
The table below shows results the student obtained for four experiments
A, B, C and D.
Experiment Volume of oxygen gas collected/cm3
Time taken for oxygen to collect/sec
A 40 35
B 40 15
C 40 10
D 40 25
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a. State which experiment A, B, C or D the reaction rate
was the highest.
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b. Explain in terms of particles, one variable (factor) which the
student could have changed in order to obtain the results shown
in the table above.
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PART B: ELECLTRICAL ENERGY
The diagram below shows the inside of a refrigerator.
a. Draw arrows on the diagram to show what happen to the air cooled
by the freezing compartment.
When the refrigerator is used for 60 minutes, 360,000 joules of
electrical energy are converted.
b. Calculate the power rating of the refrigerator.
The refrigerator has two bulbs inside. The supply voltage is 240V and the
current passing through each bulb is 0.04A.
c. Show by calculation that the resistance of one bulb is 6000Ω.
Freezing Compartment
Compartment
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The bulbs are connected in parallel.
d. Calculate the combined resistance of the two bulbs. State the formula
that you use and show your working
Formulae used:
Show calculation:
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QUESTION 4: ORGANIC COMPOUNDS, FORCE and ENERGY
PART A: ORGANIC COMPOUNDS.
The flow diagram shows the structural formula as well as the name of some
organic compounds.
The box containing the compound ethane has been completed for you.
a. Complete the diagrams by filling in where appropriate the structural
formula or the name of the compound given.
b. Name process A?
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Ethene can be produced from large alkanes at high temperature and pressure.
c. Complete the equation below for the production of ethene.
C8H18 _________________________ + ___________________
d. Name of the process use in C above?
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PART B: FORCE AND ENERGY.
A toy car drives 25m up a slope and stop. The diagram is not to scale.
a. Calculate the amount of work done by the car as it travels up the slope.
The energy gained by the car (m = 1200kg) at the top of the slope does not equal the
work done.
b. Discuss why these two forces are not equal. In your answer you should:
name the type of energy the car has, when stopped at the top of the
slope.
calculate the difference between the work done and the energy at
the top of the slope.
explain where the missing energy has gone and why this occurs.
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QUESTION 5: HEALTH and DISEASE, ELECTRICAL ENERGY.
PART A : HEALTH and DISEASE.
The table below gives the percentage of the daily nutrient requirement of a woman
supplied by eating a standard measure of the listed foods.
Food
Percentage of daily requirement
Energy Protein Vita
A
Vita
C
Vita
B1
Vita
B2 Ca Fe Niacin
Stable Food
Cooked
Taro 13 18 0 43 29 6 14 12 18
White
rice 8 12 0 0 3 1 1 2 4
Fruit Apple 3 1 1 17 4 2 1 1 1
Mango 2 3 20 150 9 2 7 2 1
Vegs
English
cabbage 1 5 1 133 6 4 9 2 2
Taro
leaves 2 17 120 333 11 23 56 19 10
a. List TWO (2) food source from the table that will be recommended for a
woman suffering from anemia
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b. Name deficiency disease is likely to develop in a child who is fed with
only cooked taro and no taro leaves.
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c. Dietary fibre is not listed in the table. Explain the importance of fibre
in our diet by providing examples of sources of fibre.
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PART B : ELECTRICITY.
The diagram below shows a coil connected to a sensitive meter.
a. Explain how this submarine detector works.
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b. State how to make the detector become more sensitive.
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QUESTION 6: METAL COMPOUNDS and GENETICS.
PART A: METAL COMPOUNDS
The diagram shown can be used to study the reaction between potassium and oxygen.
a. State why the flask becomes warm during the reaction.
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One of the compounds formed in this reaction is potassium oxide.
The electron configurations of a potassium atom and an oxygen atom are
shown below.
b. Explain the bonding in potassium oxide (In your answer you should
describe any changes in the electron configurations of the atoms, and
give the chemical formula of potassium oxide.)
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K 2,8,8,1
O 2,6
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Another compound formed in the reaction is potassium peroxide, K2O2.
When potassium peroxide is added to water the products are potassium
hydroxide and oxygen gas.
c. Write the balanced equation for the reaction of potassium peroxide and
water
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d. Describe how the student should test the gas given off to confirm that
it is oxygen.
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PART B: GENETICS.
The following pedigree shows the crossing of two white animals. They produce five
offsprings, of which, one is black and four are white.
a. Using W for white and w for black, state the genotype of the parents.
male : _______________ female : _________________
b. Explain why the expected percentage rarely occurs in situations like this.
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c. If the black offspring is crossed with a heterozygous white offspring give
the expected genotype and phenotypes to their offspring. Use a punnet
square to support your answer.
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THIS PAGE HAS BEEN DELIBERATELY LEFT BLANK.
H2 Formulae
used :
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Calculatio
n :
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