1994 - WAEC Chemistry Past Questions and Answers - page 2
11
The following will decolourize acidified potassium tetraoxomanganate (VII) solution except
A
sulphur (lV) oxide
B
but-3-ene
C
pentane
D
hydrogen sulphide
correct option: c
Users' Answers & Comments12
Polyatomicity is illustrated by molecules of
A
sulphur
B
carbon (IV) oxide
C
noble gases
D
liquefied oxygen
correct option: a
Users' Answers & Comments13
Calcium is usually extracted by the electrolysis of its
A
trioxonitrate (V)
B
tetraoxosulphate (IV)
C
oxide
D
hydride
correct option: e
Users' Answers & Comments14
When naphthalene on heating changes from the solid state directly to the gaseous state it undergoes
A
evaporation
B
sublimation
C
decomposition
D
combustion
correct option: b
Users' Answers & Comments15
Which of the following occurs when an aqueous solution of sodium hydroxide is electrolysed using graphite electrodes?
A
Sodium metal is produced at the anode
B
Sodium amalgam is formed at the cathode
C
Oxygen gas is produced at the anode
D
The grahite anode dissolves
correct option: c
Users' Answers & Comments16
If the volume of a given mass of gas at 0oC is 27.3cm3, what will be the volume of the gas at 10oC, pressure remaining constant?
A
2.73cm3
B
28.3cm3
C
37.3cm3
D
273cm3
correct option: b
Users' Answers & Comments17
Glucose can be obtained from starch by
A
hydrogenation
B
dissoiation
C
hydrolysis
D
dialysis
correct option: c
Users' Answers & Comments18
How many faradays of electricity are required to liberate 9g aluminium? (AI = 27)
A
0.1
B
0.3
C
1.0
D
2.7
correct option: c
Users' Answers & Comments19
When water is dropped on calcium carbide, the gaseous product is an
A
alkane
B
alkene
C
alkyne
D
alkanol
correct option: c
Users' Answers & Comments20
Mg2 + 2HCI(aq) → MgCI2(g) + H2(g) From the equation above what mass of hydrogen would be produced if 12.0 g of magnesium reacted completely with dilute hydrochloric acid? (H = 1, Mg = 24)
A
1.0g
B
2.0g
C
6.0g
D
12.0g
correct option: d
Users' Answers & Comments