Page 20 - 1202 Question Bank Chemistry Form 4 KSSM

Answers

CHAPTER 1
CHAPTER 1 30. A Detergent: to clean fabrics
31. A Fractional distillation is to separate (c) (i) Cosmetic consultant
Paper 1 petroleum fractions based on their (ii) Biotechnologist
differences in the boiling points. (iii) Nutritionist
1. C 32. B Ethanol boils around 78˚C, whereas 2. (a) A systematic scientific method used
2. D water boils at 100˚C. Therefore, to solve science related problems.
3. C Energy is not a matter. Therefore, it is distillation is used to separate the (b) (i) Manipulated variable: Total
not a chemical as well.
ethanol that is dissolved in the water.
4. B Fungicide is to kill fungi, pesticide is 33. B Burette can measure accurately the surface area exposed to sunlight
Responding variable: Rate of
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to kill pest.
evaporation
5. D Stabiliser is used to mix oil or fat and volume of solution up to two decimal (ii) Unfolded filter paper dries first
places in its accuracy.
water together without separating. 34. B but folded filter paper still wet.
Thickener is to thicken the food and 35. C Phenolphthalein changes from pink to (iii) The bigger the exposed surface
preservative is used to slow down the colourless when the alkaline solution area, the higher the rate of
rate of food decaying process.
is neutralised upon reaching end point.
evaporation.
6. B Sodium nitrite is a preservative to 36. B Gas coming out from the anode is (c) Making observation, making
make the meat lasts longer.
identifying
problem,
7. B oxygen gas. So, it is tested using a inference, hypothesis, identifying
glowing splinter.
making
8. B Nutritionist studies the nutritional 37. A variables, controlling variables,
value of the food. Dietitian is an 38. A planning experiment, collecting
expert in human nutrition and alters 39. A Alkali metal is very reactive and tends data, interpreting data and making
the patient's diet based on their to react with water and oxygen in the conclusion.
medical condition and individual air. 3. (a) Do not eat, drink, chase or run in the
needs. Nanotechnology engineer 40. A Hydrocarbon is flammable and should laboratory.
learns new things that can change the be kept away from heat source. Do not pour the chemicals back to
health, science, technology, and the 41. A Silver nitrate can be easily the reagent bottles.
environment on a molecular level. decomposed. Therefore, it must be (b) Use safety goggles when mixing or
Chapter 1 11. A Making inference means making 42. B Mercury, lead, arsenic, cadmium and (c) (i) To avoid dust or splashes of
9. B
heating chemicals.
kept away from sunlight.
10. D Hypothesis is to verify the inference
Keep flammable substances away
whether it is true or not.
from the heat source.
chromium are examples of heavy
metals.
explanation of an observation based
chemicals accidentally get into
43. C Poisonous chemicals must be stored
on past experience.
the eyes
properly and cannot be reached easily.
12. A
13. A In order to test the hypothesis, an
from toxic chemicals, either in
experiment is conducted. 44. D So it has to be locked in cabinet. (ii) To protect respiratory organs
the form of powder or fumes
14. D 45. C Adding water to concentrated acid (iii) To protect hands from any
may be very exothermic and the heat
15. D Hypothesis is a statement that relates released may vapourise the corrosive injury, exposure to chemicals or
the manipulated variable with the acid. Always add acid to the water infection
responding variable.
16. B (remember 3A: Always Add Acid to 4. (a) Potassium: Kept in paraffin oil
the water)
Hydrogen peroxide: Kept in dark

17. C 46. D bottles
18. B 47. B Ethanol: Kept in shady area and far
19. C 48. D from sunlight and heat source
20. B 49. D (b) (i) Phenomenon at which a person
21. B 50. A Writing a report is to keep a is exposed to mercury in a certain
22. A documentation for reference in the amount either accidentally
23. B The mass of beakers and volume of future. Data collected cannot be inhaled the mercury vapour or
beakers do not affect the result of altered and scientist should be honest touch the mercury spill until
the experiment. The type of salt used in recording the results obtained. the mercury is absorbed into the
(soluble or insoluble), will affect the More measurements should be done body through the skin
result of experiment and must be kept to get average value of measurement (ii) Nausea and vomiting
constant.
24. C to increase the accuracy. (iii) Inform the accident to the
teacher
immediately.
Next,
25. B Eyewash is a safety equipment in the make the spill site a restricted
laboratory. Paper 2
26. A Safety goggles is actually a personal area. Sprinkle sulphur powder
to cover up the mercury spill.
protective equipment a person should Section A Lastly, contact the Fire and
wear when handling dangerous 1. (a) A field of science that studies the Rescue Department for further
experiment. structures, properties, compositions
27. A and interactions between matters. action.
28. C Eyewash is a safety equipment to (b) (i) Insecticide, colouring and Section B
clean the parts of the eye in case of detergent 1. (a) Put some alkaline quicklime or
accident. (ii) Insecticide: to kill insect
29. D Fume chamber is a cupboard that Colouring: to give colour or slaked lime to neutralise the acidity
of the soil.
is used to carry out experiment that restore colour loss during food
involves the release of toxic gas. processing
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