1997 - JAMB Chemistry Past Questions and Answers - page 3
21
What is the oxidation number of Z in K3ZCl6?
A
-3
B
+3
C
-6
D
+6
correct option: b
Users' Answers & Comments22
2H2S(g) + SO2(g) + H2O(I) → 3S(s) + 3H2O(I)..........(i) 3CuO(s) + 2NH3(g) → 3Cu(s) + 3H2O(I) + N2(g).........(II) In the equations above, the oxidizing agent (I) and the reducing agent in (II) respectively are?
A
H2S and NH3
B
SO2 and CuO
C
SO2 and NH3
D
H2S and CuO
correct option: c
Users' Answers & Comments23
2SO2(g) + O2(g) 2SO3. In the reaction above, the standard heats of formation of SO2(g) and SO3(g) are -297 KJ mol-1 respectively. The heat change of the reaction is?
A
-99 kJ mol-
B
-198 kJ mol-
C
+198 kJ mol-
D
+683kJ mol-
correct option: b
2SO2 + O2 → 2SO3
2(-297) 2(-396)
-594 -792
Heat change = heat of product - reactants = -792 - (-594) = 198kj mol-
Users' Answers & Comments2(-297) 2(-396)
-594 -792
Heat change = heat of product - reactants = -792 - (-594) = 198kj mol-
24
If the rate law obtained for a given reaction is rate = k(X)n (Y)m, what is the overall order of the reaction?
A
nm
B
n/m
C
n + m
D
n - m
correct option: c
Users' Answers & Comments25
One method of driving the position of equilibrium of an endothermic reaction forward is to?
A
increase temperature at constant pressure
B
dcrease pressure at constant temperature
C
cool down the apparatus with water
D
decreases temperature at constant pressure
correct option: a
Users' Answers & Comments26
Oxidation of concentrated hydrochloric acid with manganese (IV) oxide liberates a gas used in the?
A
manufacture of tooth pastes
B
treatment of simple golitre
C
vulcanization of rubber
D
sterilization of water
correct option: d
Users' Answers & Comments27
mE + nF → pG + qH. In the equation above, the equilibrium constant is given by?
A
(E)m(F)n/ (G)n(H)q
B
(E)(F) / (G)(H)
C
(G)p(H)q / (E)m(F)n
D
(G)(H) / (E)(F)
correct option: c
Users' Answers & Comments28
A compound that will NOT produce oxygen on heating is?
A
potasium dioxonitrate (III)
B
lead (IV) oxide
C
potassium trioxochlorate (V)
D
potassium trioxonitrate (V)
correct option: a
Users' Answers & Comments29
Coal gas is made up of carbon (II) oxide, hydrogen and?
A
nitrogen
B
air
C
argon
D
methane
correct option: d
Users' Answers & Comments30
2X(aq) + MnO2(s) + 4H+(aq) → X2(g) + Mn2+(aq) + 2H2O.
The reaction above can be used for the laboratory preparation of all halogens except fluorine because it is?
The reaction above can be used for the laboratory preparation of all halogens except fluorine because it is?
A
a poisionous gas
B
an oxidizing agent
C
electronegative in nature
D
highly reactive
correct option: d
Users' Answers & Comments