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.
24.5 mole per dm3
0.2 mole per dm3
10.0 mole per dm3
20.0 mole per dm3
2.0 mole per dm3
Correct answer is E
9.8 gms KCIO3 dissolves in 40 cm3 of H.
In 100 cc we have (9.8)/(40) x (100)/(1) = 24.5 gm KCIO3
In 1000 cc we have 10 x 24.5
or 245 gms of KCIO3.
But mol wt of KCIO3 is 122.5
Solubility of KCIO3 is (245)/(122.5) = 2 moles per dm3 (E)
When air is passed through alkaline pyrogallol and then over quicklime, the only gases left are?
nitrogen and carbondoxide
the rare gases
nitrogen and oxygen
nitrogen and the rare gases
nitrogen, carbonioxide and the rare gases
Correct answer is D
No explanation has been provided for this answer.
some unburnt phosporus
P2O5 vapour
some oxygen
rare gases
carbondioxide
Correct answer is D
No explanation has been provided for this answer.
six atoms of X will combine with one of Y
two atoms of X will combine with six of Y
one atom of X will combine with two of Y
two atoms of X will combine with one of Y
one atom of X will combine with six of Y
Correct answer is C
- When an element in group 1 takes part in a reaction, its atoms lose their outer electron and form positively charged ions , called cations .
- Group 6 elements, have 6 valence electrons and will tend to take 2 electrons and have a valency of -2.
- Hence; one atom of element X will require two atoms of Y
- To form a compound XY\(_2\)
sodium nitrate
mercuric nitrate
lithium nitrate
silver nitrate
potassium nitrate
Correct answer is D
No explanation has been provided for this answer.