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 statements about the standard hydrogen electrode is not correct?
The hydrogen gas is at a pressure of 1 atmosphere
A solution containing 1 mol dm-3 of H+ (aq) ions is used
A platinum electrode is used
The temperature is kept at 20 °C
Correct answer is D
The standard hydrogen electrode consists of hydrogen gas at 25oC
Alkanols can be manufactured from alkenes by the initial reaction of alkenes with
bromine in tetrachloromethane
concentrated tetraoxosulphate(VI) acid
aqueous potassium tetraoxomanganate(VII).
sodium hydroxide solution.
Correct answer is B
An alkene reacts with conc. H2SO4 to yield an alkyl hydrogen tetraoxosulphate (VI). The compound formed undergoes hydrolysis when boiled with water to yield an alcohol.
Which of the following compounds would react rapidly with bromine?
Benzene
Hexane
Hexene
Hexanol
Correct answer is C
The addition of bromine to most alkenes is so fast that when bromine is added dropwise to a solution of the alkene the red bromine color disappears almost immediately. In fact, this discharge of color is a useful qualitative test for alkenes.
What amount of electricity is required to deposit one mole of aluminium from a solution of AlCl3?
One Faraday
One ampere
Three Faradays
Three amperes
Correct answer is C
AlCl3 → Al3+ + 3Cl-
At cathode:
Al3+ + 3e- → Al
3 mole of electrons corresponds 3 F charge
So, required charge =3 F
The following compounds are condensation polymers except
nylon
protein
starch
polyethene
Correct answer is D
Condensation polymers are any kind of polymers whose process of polymerization involves a condensation reaction.