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 represents a precipitation reaction?
H2SO4 + NaCl \(\to\) NaHSO4 + HCl
Fe +H2SO4 \(\to\) FeSO4 + H2
4HCl + MnO2 \(\to\) MnCl2 + 2H2O + Cl2
Na2SO4 + pb(NO3) \(\to\) PbSO4 + 2NaNO
CuO +2HCl \(\to\) Cl2 + H2O
Correct answer is D
No explanation has been provided for this answer.
5
15
25
35
50
Correct answer is C
CaCO3 + CaO \(\to\) 2CaO + 2CO2
44gm of CO3 is liberated by 100gm of CaCO3
0.33gm of CO2 will be liberated by \(\frac{100}{44}\) x 0.33
= 0.75 of CaCO3
Amount of CaO = 1 - 0.75
= 0.25
% of CaO = \(\frac{0.25}{1} \times \frac{100}{1}\)
= 25%
0.54g
1.08g
1.62g
2.16g
3.24g
Correct answer is D
Same period, Same current
\(Cu^{2+} + 2e^- → Cu; 2Ag^+ + 2e^-\) → Ag
From the equation above, 2 mol Ag ≡ 1 mol Cu
But 0.63g Cu = \(\frac{0.63}{63}\) = 0.01mole Cu
Hence 0.002 mole Ag is deposited
mass of Ag deposited = 0.002 x 108 = 2.16g.
In the above experiment, the litmus paper will initially
be bleached
turn green
turn red
turn blue
turn black
Correct answer is D
No explanation has been provided for this answer.
0.457g
0.500g
0.882g
0.914g
1.00g
Correct answer is A
Time = 2hrs = 120mins = 120 x 60secs =7200secs.
current = 0.193amps
Quantity of electricity = 7200 x 0.193 = 1389.6
2 x 96,500 deposits 63.5 gms of Cu
1389.6 will deposit \(\frac{63.5 \times 1389.6}{2 \times 96500}\)
= 0.457g