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.
Anhydrous CaCl2
concentrated NaCO4
dilute NaOH
concentrated H2SO4
Correct answer is A
To purify the distillate of impurities like unreacted ethanol, acids, water and ethoxyethane.
Adding anhydrous calcium chloride and leave it to stand for a day to remove any water present
in the mixture.
The process that occurs when two equivalent forms of a compound are in equilibrium is
Isotopy
Resonance
Isomerism
Reforming
Correct answer is B
Resonance involves two forms of a compound.
Isomerism involves two or more forms of an element.
Reforming involves the rearrangement of molecule.
This deals with a two forms of a molecule where the chemical connectivity is the same but the electrons are distributed differently around the structure.
The acid anhydride that will produce weak acid in water is
SO3
NO2
SO2
CO2
Correct answer is D
H2CO3 is an example of a weak acid while H2SO4 and HNO3 are examples of a strong acid.
CO2 combines with water to give a weak trioxocarbonate (IV) acid.
CO2 + H2O → H2CO3
CaCO3
Na2CO3
Na2SO4
CaSO4
Correct answer is A
Permanent hardness in water= Mg & Ca Sulphate.
Temporary hardness in water= Mg & Ca Carbonate.
Temporary hardness of water is caused by Magnesium and calcium hydrogencarbonate. It is formed when rainwater containing dissolved CO2 flows over deposit of CaCO3
i.e CaCO3 + CO2 + H2O → Ca(HCO3)2
