WAEC Past Questions and Answers - Page 1403

7,011.

High relative humidity in a brooder house could lead to

A.

Reduced feed intake

B.

Production of dry litter

C.

Build up of pests and diseases

D.

Heat stress

Correct answer is C

High humidity in a brooder house creates a conducive environment for the growth and multiplication of pests and diseases. It can also lead to the development of mould and fungi, which can be harmful to the chicks.

7,012.

Study the table below and use it to answer the question

 Cost Price (N)  Useful life (Years)  Salvage value (N)  Annual depreciation (N)  Total depreciation
 20000  Y  5000  1000 annum  15000
 60000  10  18000  4200 annum  Z

The total depreciation represented by Z in the illustrated table is

A.

N42,000

B.

N78,000

C.

N22,200

D.

N55,800

Correct answer is A

Cost Price (N) = 60000
Salvage value (N) = 18000
Annual depreciation (N) = 4200
Useful life (Years) = 10
The formula to calculate the total depreciation is:
Total depreciation = (Cost Price - Salvage value) / Useful life
Now, let's plug in the values:
Total depreciation = (60000 - 18000) / 10
Total depreciation = 42000 / 10
Total depreciation = 4200
Therefore, the total depreciation represented by Z in the table is N 42,000.

7,013.

Which of the following compounds will leave a metal residue when heated?

A.

Cu(NO3)2

B.

AgNO3

C.

K2CO3

D.

CaCO3

Correct answer is B

No explanation has been provided for this answer.

7,014.

CuSO45H2O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by

A.

evaporation to dryness

B.

using chromatography

C.

precipitation

D.

crystallization

Correct answer is D

No explanation has been provided for this answer.

7,015.

Equal amounts of marble chips are reacted separately with 100cm3 of hydrochloric acid of different concentrations. If all the marble chips reacted; which of the following remained the same in each case?

A.

Average rate of evoluton of gas

B.

Total mass of gas evolved during the reaction

C.

Time taken for the reaction to reach completion

D.

Initial reaction rates

Correct answer is B

The total mass of gas evolved during the reaction will remain the same in each case. This is because the amount of marble chips is the same in each case, and the reaction goes to completion. Therefore, the same amount of gas will be produced in each case, regardless of the concentration of the hydrochloric acid.