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 is true? When the potassium atom forms its ion
it gains one electron and becomes neutral
its atomic number decreases
it achieves electronic configuration of orgon
it loses one proton
it loses one neutron
Correct answer is C
No explanation has been provided for this answer.
Na+ ions are discharged at the cathode
Hydrogen ions are discharged at the cathode
the concentration of sodium hydroxide decrease at both electrode compartments
the concentration of sodium hydroxide increases at the cathode only
the concentration of sodium hydroxide increases at the anode only
Correct answer is B
Electrolysis of conc NaOH using platinum elcetrodes:
At the cathode, Hydrogen gas is evolved
at the anode, Oxygen gas is evolved.
fractional distillation
filtration followed by distillation
neutralization with sodium hydroxide followed by distillation
esterification with ethanol followed by distillation
neutralization with sodium hydroxide followed by filtration
Correct answer is E
Water added to an acid decreases its pH, hence, methanoic acid and water (azeotropes with very close boiling points) will be more acidic. Hence, addition of sodium hydroxide forms a salt and water. Then filtration can be done easily.
calcium carbonate is formed which on reaction dissolves
calcium hydrogen carbonate is precipitated and then dissolves
calcium carbonate is formed which on reaction with further carbondioxide forms solube calcium hydrogen carbonate
concentration of the solution has occurred with the deposition of calcium hydroxide
the solution has become saturated and solid carbondioxide has been deposited
Correct answer is C
No explanation has been provided for this answer.
The oxidation state of manganese in potassium permanganate is
+7
+5
+3
+2
+1
Correct answer is A
No explanation has been provided for this answer.