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 allotropy of carbon used in the decolourization of sugar is
Graphite
Soot
Charcoal
Lampblack
Correct answer is C
No explanation has been provided for this answer.
Which of the following shows little or no net reaction when the volume of the system is decreased?
H2(g) + I2(g) ↔ 2HI(g)
2NO2(g) ↔ N2O4(g)
PCl5(g) ↔ PCl3(g) + Cl2(g)
2O3(g) ↔ 3O2(g)
Correct answer is A
No explanation has been provided for this answer.
N2O4(g) ↔ 2NO2(g)
In the endothermic reaction above, more product formation will be favoured by
a constant volume
an increase in pressure
a decrease in pressure
a decrease in volume
Correct answer is C
No explanation has been provided for this answer.
Which of the following hydrogen halides the highest entropy value?
HF
HCl
HBr
HI
Correct answer is A
No explanation has been provided for this answer.
-503.7 kJ
-282.6 kJ
+282.6 kJ
+503.7 kJ
Correct answer is B
Energy change (ΔH) = 2ΔHCO2 - (2ΔHCO + ΔHO)
= 7x - 393 - (7 * 110.4 + 0)
= -393 + 110.4 = -282.6 kJ