BECE Past Questions & Answers – 1997 (SCIENCE)

August 1997

SCIENCE

SECTIONB ESSAY
1hour [60 marks]

Answerthreequestionsonlyfrom this section.
Illustrate your answers wherever possible, with large, clear and fully labelleddiagrams. Creditwill be given for clarity of expression and orderlypresentation ofmaterial.
All questions carry equal marks

1. (a) Definethe term osmosis

(b)
Statetwo examples of everydayobservations which can beexplained in terms of capillaryaction.

(c) (i) (ii) Name thethreeprocesses bywhich heat can betransferred. Name three appliances which usethermostat.

(d)
(i) (ii)
What is a saturated solution?
Statewhethereach of thefollowingis a solution, suspension or acolloid:
Clayinwater
Sugar in water Ammoniain water Powdered chalk in water
Potassiumpermanganatein water
Soap in water

2. (a) Copythe table below andwritethe usual hostof each of theparasitesgivenin thespaces provided.

Parasite Host
Plasmodium
Capsids

Tapeworm
Dodder

(b) (i) Name three classes of food
(ii) Foreach of the following food substances,give themajor class offoodto which it
belongs: starch, milk, margarine, sugar

(c) Write the chemical formula foreach of thefollowingcompounds: (i) calcium hydroxide
(ii) zinc chloride[zinc (II)chloride] (iii) (iv) (v) sodium nitrate [sodium trioxonitrate (V)],
calcium carbonate [calcium trioxocarbonate (IV)] potassiumsulphate [potassium tetraoxosulphate (VI)]

(d)
(i) (ii)
Definethe term viscosity
Describean experimentyou performed to comparethe viscosities oftwo liquids A and B

3. (a) (i) Definethe terms humidityandwind
(ii) Name theinstruments used to measurehumidityand the speed of wind

(b) (i) What is a galaxy?
(ii) Giveone exampleofgalaxy

(c) Statethreemethods bywhich food can bepreserved.

(d) Explain whyitis better to wearwhite clothes thanblack clothes on asunnyday.

(e) Write down thenames ofthe new substances formed when the followingsubstances are allowed to react:
(i) Sodiumhydroxide and dilute sulphuric acid
(ii) Calcium carbonate and dilute hydrochloricacid
(iii) Ammonia and dilute sulphuric acid

4. (a) Defin ethefollowingterms and givean example each
(i) Herbivore
(ii) Carnivore
(iii) Omnivore

(b) Twodrycells connectedin parallel arein turn connected in series with abulb and switch.

Drawacircuitdiagramtoillustratethisarrangement

(c) Listfourgardentools

(d) Whatpropertyofwatercausesmosquitolarvaetofloatonit?

(e) Describeanexp CLICK TO VIEW ANSWERS TO PART 2