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 metals would readily displace hydrogen from steam?
Copper
Lead
Magnesium
Silver
Correct answer is C
In the electrochemical series, H+ is above all the other elements in the series except Magnesium. Hence, only Mg2+ can displace hydrogen from a reaction.
conservation of mass
definite proportion
multiple proportion
reciprocal proportion
Correct answer is C
Law of multiple proportions, statement that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.
A sample of a gas may be identified as chlorine if it turns
damp blue litmus paper red
lime water miky
lead ethanoate paper black
starch iodide paper blue-black
Correct answer is D
A test for chlorine is to place damp starch-iodide paper into a test tube of chlorine. A positive result for chlorine is indicated by the paper turning from white to blue-black.
The formula of mercury (l) dioxonitrate (III) is
HgNO3
Hg2NO2
Hg2(NO2)2
Hg(NO3)2
Correct answer is C
No explanation has been provided for this answer.
2,3 and 4
2, 4 and 3
1,2 and 3
1, 3 and 5
Correct answer is A
xCH3OH + yO2 → 2CO2 + zH2O
Balancing the equation, we have
C = x (on the left) and 2 (on the right)
⇒ x = 2
2CH3OH + yO2 → 2CO2 + zH2O
On the left, H = 8 and on the right = 2z
⇒ 2z = 8 ; z = 4
2CH3OH + yO2 → 2CO2 + 4H2O
On the right, O = 4 + 4 = 8.
On the left, O = 2 + 2y
⇒ 2 + 2y = 8
2y = 6 ; y = 3
x, y, z = 2, 3, 4.