2013 - JAMB Chemistry Past Questions and Answers - page 1
1
The presence of an impurity in substance will cause the melting point to
A
be zero
B
reduce
C
increase
D
be stable
correct option: b
Users' Answers & Comments2
What volume of carbon (ll) oxide is produced by reacting excess carbon with 10 dm3 of oxygen?
A
5 dm 3
B
20 dm 3
C
15 dm 3
D
10 dm 3
correct option: b
Users' Answers & Comments3
The rate of diffusion of a gas Y is twice that of Z If the relative molecular mass of Y is 64 and the two gases diffuse under the same conditions, find the relative molecular mass of Z
A
32
B
4
C
8
D
16
correct option: d
\(\sqrt{y}\) = 2x
\(\sqrt{Z}\) = x
\(\frac{rz}{ry}\) = \(\sqrt{\frac{my}{mz}}\)
\(\frac{2x}{x}\) = \(\sqrt{\frac{64}{mz}}\)
\(\frac{4}{1}\) = \(\frac{64}{mz}\)
mz = \(\frac{64}{4}\)
mz = 16
Users' Answers & Comments\(\sqrt{Z}\) = x
\(\frac{rz}{ry}\) = \(\sqrt{\frac{my}{mz}}\)
\(\frac{2x}{x}\) = \(\sqrt{\frac{64}{mz}}\)
\(\frac{4}{1}\) = \(\frac{64}{mz}\)
mz = \(\frac{64}{4}\)
mz = 16
4
The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is
A
carbon-14
B
phosphorus-32
C
cobalt-60
D
iodine-131
correct option: c
Users' Answers & Comments5
The shape of the carbon (lV) oxide molecule is
A
pyramidal
B
linear
C
angular
D
tetrahedral
correct option: b
Users' Answers & Comments6
Which of the following molecules is held together by hydrogen bond?
A
CH4
B
HBr
C
H2SO4
D
HF
correct option: d
Users' Answers & Comments7
The bond formed between two elements with electron configurations 1s2 2s2 2p6 3s2 and 1s2 2s2 2p4 is
A
metallic
B
covalent
C
dative
D
ionic
correct option: d
Users' Answers & Comments8
The constituent of air that acts as a diluent is
A
nitrogen
B
carbon (IV) oxide
C
noble gases
D
oxygen
correct option: a
Users' Answers & Comments9
Steam changes the colour of anhydrous cobalt (ll) chloride from
A
white to red
B
blue to white
C
blue to pink
D
white to blue
correct option: c
Users' Answers & Comments10
An example of a hygroscopic substance is
A
CuO (S).
B
MgCL2(S).
C
CaCL2(S).
D
NaOH(S).
correct option: a
Users' Answers & Comments