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.
Which of the following substances is a mixture?
Granulated sugar
Seawater
Sodium chloride
Iron filling
Correct answer is B
A Mixture contains two or more constituents which can be easily separated by physical methods. Examples include Air, Soil, Palm oil, Sea water, Blood, Crude oil, etc
Oxyethene
Oxyhydrocarbon flame
Oxyacetylene flame
Oxymethane flame
Correct answer is C
The reaction of calcium carbide with water, producing acetylene and calcium hydroxide, was discovered by Friedrich Wöhler in 1862. This reaction was the basis of the industrial manufacture of acetylene, and is the major industrial use of calcium carbide.
Acid
Ester of alkanoic acid
Alkali
Alkanol
Correct answer is C
A lye is a metal hydroxide traditionally obtained by leaching wood ashes, or a strong alkali which is highly soluble in water producing caustic basic solutions / an alkaline solution that is used to make soaps. "Lye" most commonly refers to sodium hydroxide (NaOH), but historically has been used for potassium hydroxide (KOH).
What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke?
Steam distillation
Destructive distillation
Liquefication
Hydrolysis
Correct answer is B
Destructive distillation of a tonne of coal can produce 700 kg of coke, 100 liters of liquor ammonia, 50 liters of coal tar and 400 M\(^3\) of coal gas
What are the possible oxidation numbers of an element if its atomic number is 17?
-1 and 7
-1 and 6
-3 and 5
-2 and 6
Correct answer is A
The element with atomic number 17 is Chlorine with a valency of -1, that is it needs to receive an electron or possibly lose seven electrons to obey the octet rule.