Program Galus Sains SPM SMK Kuala Pegang 2009Skema Jawapan Bahagian C – Soalan 10

________________________________________________________________________Marking scheme for Section C

Skema pemarkahan untuk Bahagian CQuestion 1Soalan 1

(a) Hypothesis (Carbon dioxide/ gas release a by) yeast can increase the height of a bread dough [ 1 mark ]

(b) (i)Aim To show that the effect of ( carbon dioxide releases from) yeast on the height of a bread dough. [ 1 mark ]

(b)(ii)Variables

(a) Constant

Mass of wheat flour [ 1 mark ]

(b) Manipulated

The Presence of yeast [ 1 mark ]

(c) Responding

Height of dough [ 1 mark ]

(b)(iii)Apparatus and material

Distilled water, beaker, wheat flour, yeast [ 1 mark ]

(b)(iv)Procedure

1. Mix the wheat flour , yeast and sugar in a beaker2. Add water a little at a time to the mixture and stir the mixture to form a paste.3. (After that, take out of the beaker onto the work surface.4. Knead the mixture of the paste and yeast.)5. Fill the beaker with (the kneaded) dough.6. Step 1 to 5 are repeated but no yeast is added - pt 27. Both beakers are left in a warm humid place for 20 minutes 8. The height of the dough is measured

(b)(iv)Tabulation of data

Presence of yeastHeight of dough (cm)

Intial experiment Final experimentPresentAbsent

[1 mark]

1

[ 1 mark ]

Max 2 marks

pt

Pt 1

Pt 3

Pt 4

Program Galus Sains SPM SMK Kuala Pegang 2009Skema Jawapan Bahagian C – Soalan 10

________________________________________________________________________Question 2

(a) Hypothesis 1. Microorganisms grow rapidly in moist condition. Mikroorganisma tumbuh dengan pesat di kawasan lembap.

2. Humidity is needed for the growth of microorganisms Kelembapan diperlukan untuk pertumbuhan mikroorganisma

[ 1 mark ](b)(i)Aim To study the effect of humidity on the growth of microorganisms

Untuk mengkaji kesan kelembapan ke atas pertumbuhan mikroorganisma [ 1 mark ]

(b)(i) Variables

(a) Constant

1. Type/ size of bread Jenis/saiz roti2. Suhu Temperature [ 1 mark ]

(b) Manipulated

Presence of waterKehadiran air [ 1 mark ]

(c) Responding

The growth of microorganisms/fungi/mucorPertumbuhan mikroorganisma/fungi/mukor [ 1 mark ]

(b)(iii)Apparatus and material

(2 pieces of) bread, water, clear plastic bag (2 keping) roti, air, beg plastik lutsinar [ 1 mark ]

(b)(iv)Procedure

1. Prepare 2 piece of bread with the same size and label A and B. pt 12. Bread A is sprinkled with water and placed in a clear plastic bag.3. Bread B is kept dry and placed in the clear plastic bag4. Both plastic bags are kept in a dark cupboard for two days.5. The growth of microorganisms/fungi/mucor is observed and recorded in the table.

1. Sediakan dua keping roti yang sama saiz dan dilabel A dan B2. Roti A direnjis dengan air dan diletakkan di dalam plastic lutsinar .3. Roti Bi dibiarkan kering dan dimasukkan ke dalam plastik lutsinar 4. Kedua-dua beg plastik diletakkan di dalam almari selama 2 hari.5. Pertumbuhan mikroorganisma/kulat/mukor diperhatikan dan direkodkan ke dalam jadual.

2

pt

Pt 2

Max 2m

Pt 3

Pt 4

Program Galus Sains SPM SMK Kuala Pegang 2009Skema Jawapan Bahagian C – Soalan 10

________________________________________________________________________(b)(v) Tabulation of data

BreadRoti

Presence of waterKehadiran air

Growth of microorganisms/ fungi/ mucorPertumbuhan

mikroorganisma/kulat/mukorA Present

HadirB Absent

Tidak hadir [1 mark ]

(b)(vi)Conclusion

Water is needed for the growth of microroganisms/ fungi/mucorAir diperlukan untuk pertumbuhan mikroorganisma/ fungi/mukor [1 mark]

Question 3(a) Hypothesis The bigger the mass of an object, the bigger its inertia.

[ 1 mark ]

(b)(i)Aim To study the relationship between mass and inertia. [ 1 mark ]

(b)(i) Variables

(a) Constant

Size / volume of tinLength of ropeHeight of tin hang [ 1 mark ]

(b) Manipulated

Mass of tin [ 1 mark ]

(c) Responding

The difficulty to push and stop the tin [ 1 mark ]

(b)(iii)Apparatus and material

Tin, tope, sand, wood [ 1 mark ]

(b)(iv)Procedure

1. Two tins are prepared and label A and B. pt 12. Tin A is filled with sand and tin B is left empty. Pt 23. Both tins are hung using ropes of the same length to a wood. Given pt 14. Each tin is pushed from the same height and after a while, both tins are stopped from swinging.5. The tin which is difficult to swing and stop are observed pt 3

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Program Galus Sains SPM SMK Kuala Pegang 2009Skema Jawapan Bahagian C – Soalan 10

________________________________________________________________________(b)(v) Tabulation of data

Tin Mass of tin The difficulty to swing or stop the tinA BigB Small

[ 1 mark ]

(b)(vi)Conclusion

The bigger the mass of the tin, the bigger its inertia. [ 1 mark ]

Question 4:

(a) Hypothesis 1. Weight of object decreases when it is immersed in a liquid/water.2. When an objeck is immersed in water, its weight decreases [ 1 mark ]

(b)(i)Aim To study the changes of object’s weight when it is immersed in water. [ 1 mark ]

(b)(i) Variables

(a) Constant

Size of wooden blockType of liquid [ 1 mark ]

(b) Manipulated

Length/ depth of wooden block immerse in water [ 1 mark ]

(c) Responding

Weight of wooden block [ 1 mark ]

(b)(iii)Apparatus and material

Newton spring, wooden block, water, beaker, string,retort stand [ 1 mark ]

(b)(iv)Procedure

4

Newton springNeraca spring

Retort standKaki retort

String

Wooden block

Water

beaker

Pt 1

Pt 3

Program Galus Sains SPM SMK Kuala Pegang 2009Skema Jawapan Bahagian C – Soalan 10

________________________________________________________________________1. Wooden block is tied to a string2. Hang the Newton spring to a retort stand pt 1 // diagram3. Using the newton spring, measure the weight of wooden block in air pt 2 4. Immerse the wooden block partially in the water and measure its weight. Pt 3// diagram5. Step 4 is repeated by immersing fully the wooden block in the water . pt 4

(b)(v) Tabulation of data

Length of wooden block immerse in water

Weight of wooden block

PartialFull

[ 1 mark ]

Question 5

(a) Hypothesis Different metal shows different reactivity with dilute acid [ 1 mark ]

(b)(i)Aim To study the reactivity of metals with (hydrochloric) acid [ 1 mark ]

(b)(i) Variables

(a) Constant

Type of acidConcentration of acidMass of metal [ 1 mark ]

(b) Manipulated

Type of metal [ 1 mark ]

(c) Responding

Reactivity of metal [ 1 mark ]

(b)(iii)Apparatus and material

magnesium powder, aluminium powder, zinc powder, dilute hydrochloric acid, test tube [ 1 mark ]

(b)(iv)Procedure

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Program Galus Sains SPM SMK Kuala Pegang 2009Skema Jawapan Bahagian C – Soalan 10

________________________________________________________________________(b)(v)Tabulation of data

dilute dilute dilute hydrochloric hydrochloric hydrochloric acid acid acic magnesium aluminium zinc powder powder powd A B C

1. Prepare three test tubes A, B and C2. Pour dilute hydrochloric acid in test tube A, B and C – pt 13. Put:(a) Magnesium powder in test tube A(b) Aluminium powder in test tube pt 2(c) Zinc powder in test tube C4. Observe the reactivity of the metals with dilute hydrochloric acid and record in table. Pt 3

(b)(vi)Type of metal Reactivity of metalMagnesiumAluminium

Zinc [ 1 mark ]

(b)(vii)Conclusion

Different metal shows different reactivity with dilute acid [ 1 mark ]

6

Program Galus Sains SPM SMK Kuala Pegang 2009Skema Jawapan Bahagian C – Soalan 10

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