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.
The gas that is most useful in protecting humans against solar marathon is
chlorine
ozone
carbon IV oxide
hydrogen sulphide
Correct answer is B
The ozone layer or ozone shield refers to a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It contains high concentrations of ozone (O3) relative to other parts of the atmosphere, although still very small relative to other gases in the stratosphere
In the industrial production of H2 from water gas the CO2 produced along with the H2 is removed by
washing under pressure
drying over phosphorus (V) oxide
passing the mixture to the limewater
using ammonical copper (I) chlorine
Correct answer is A
Washing under pressure is an action in the industrial production of H. Options B,C,D will not yield Co and H
Iron is often galvanized in order to
Make it more malleable
Remove the impurities unit
Protect it against corrosion
Render it passive
Correct answer is C
Iron is galvanized with zinc covering to protect it against corrosion. Option A, B, D are the main reasons iron is galvanized
Which of these require crystallization most?
Drug making
Cement making
Paint making
Perfume making
Correct answer is A
Crystallization is required the most in industries where the purity of their products is important e.g in the manufacture of drugs and in sugar production. Options B,C and D do not undergo crystallization
The filter in the cigarette reduce the nicotine construct by
burning
adsorption
evaporation
absorption
Correct answer is B
The acetate and paper modify the particulate smoke phase by particle retention (filtration), and finely divided carbon modifies the gaseous phase (adsorption)