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.
0.1
0.5
2.0
4.0
Correct answer is C
The rate of dimension of a gas inversely proportional to the square root of its molecular mass or its density, which is Graham's Law of diffusion of gas.
R ∝ \(\frac{1}{\sqrt{Mm}}\) or R ∝ \(\frac{1}{\sqrt{D}}\)
Dx = 0.5gdm-3, Dy = 2gdm-3
R= \(\frac{K}{\sqrt{D}}\)
R\(\sqrt{D}\) = k
R1\(\sqrt{D_1}\) = R1\(\sqrt{D_2}\)
Rx\(\sqrt{D_x}\) = Ry\(\sqrt{D_y}\)
\(\frac{R_x}{R_y}\) = \(\frac{\sqrt{D_y}}{\sqrt{D_x}}\)
= \(\frac{\sqrt{2}}{\sqrt{0.5}}\)
= 2.0
The reddish–brown rust on iron roofing sheets consists of
Fe3 + (H2O)6
FeO.H2O
Fe2O3.XH2O
Fe3O4.2H22O
Correct answer is C
Iron [Fe] reacts with H2 in the presence of oxygen to form a rust.
4Fe + 3O2 → 2 Fe2O2
Fe2O3 + H2O → Fe2O3.H2O
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