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 IUPAC nomenclature of the structure above is
3-methybut-3-ene
2-methylbut-1-ene
2-ethylprop-1-ene
2-methylbut-2-ene
Correct answer is B
CH2CH2 - CCH3CH2
Start the numbering from the terminal carbon.
0.300g
0.250g
0.2242g
0.448g
Correct answer is D
M = \(\frac{\text{Molar mass × Quantity of Electricity}}{\text{96500 × no of charge}}\)
= \(\frac{MmIT}{96500n}\)
Copper II Chloride = CuCl2
CuCl2 → Cu2+ + 2Cl2
Mass of compound deposited = \(\frac{\text{Molar mass × Quantity of Electricity}}{\text{96500 × no of charge}}\)
Q = IT
I = 0.5A
T = 45 × 60
T = 2700s
Q = 0.5 × 2700
= 1350c
Molarmass = 64gmol-1
no of charge = + 2
Mass = \(\frac{64 \times 1350}{96500 \times 2}\)
Mass = 0.448g
fused CaO
H2O
NaOH
Concentrated H2SO4
Correct answer is D
In the preparation of sulphur dioxide by the action of dilute acids on sulphates and bisulphites. conc H2SO4 helps to release SO2 from the mixture.
The setup represents the production of sulphur dioxide
SO3
SO2
S
H2S
Correct answer is B
The setup represents the production of sulfur dioxide. And the cylinder marked X is SO2
Cu2S(g) + O2(g) → 2Cu + SO2(g)
What is the change in the oxidation number of copper in the reaction?
0 to + 2
0 to + 1
+ 1 to 0
+ 2 to + 1
Correct answer is C
In the reactant;
Cu2S
2 Cu - 2(1) = 0
2 Cu = 2
Cu = \(\frac{2}{2}\)
Cu = +1
In the product, Cu
Cu = O
The oxidation number of Cu in Cu2S and Cu respectively is +1 and 0 respectively