Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
In which of the following reactions does reduction takes place
Fe2+ - e- → Fe3+
2O2- →O2 + 4e-
Cr – 2e- → Cr2+
2H+ + 2e- → H2
Correct answer is D
No explanation has been provided for this answer.
Phosphorus is stored under water to prevent it from
Dehydrating
Becoming inert
Smelling
Catching fire
Correct answer is D
No explanation has been provided for this answer.
The chemical used for coagulation in water purification is
Aluminium tetraoxosulphate (VI)
Copper tetraoxosulphate (VI)
Sodium tetraoxosulphate (VI)
Calcium tetraoxosulphate (VI)
Correct answer is A
No explanation has been provided for this answer.
Environmental pollution is worsened by the release from automobile exhausts of?
Water vapour
Steam
Smoke
Heavy metals
Correct answer is C
Carbon monoxide (CO) popularly known as the Black smoke from exhaust fumes of vehicles (cars, trucks and tricycles) and generators is a toxic gas released into the atmosphere.
What is the decrease in volume of air when pyrogallol is shaken with 30.00cm3 of air ?
15.00cm3
6.30cm3
0.63cm3
0.06cm3
Correct answer is B
% volume of O2 in air = 21%
∴ (21/100) * 30 = 6.3