1999 - JAMB Chemistry Past Questions and Answers - page 2
11
The method that can be used to convert hard water to soft water is
A
chlorination
B
passage over activated charcoal
C
the use of an ion-exchange resin
D
aeration
correct option: c
Users' Answers & Comments12
1s2, 2s2, 2p6, 3s2, 3p6, 3d7, 4s2
An element with the electronic configuration above is a
An element with the electronic configuration above is a
A
non-metal
B
metal
C
transition element
D
group two element
correct option: c
Users' Answers & Comments13
Given that electronegativity increases across a period and decreases down a group in the periodic table, in which of the following compounds will the molecules be held together by the strongest hydrogen bond?
A
HF(g)
B
NH3(g)
C
CH4(g)
D
HCl(g)
correct option: a
Users' Answers & Comments14
0.25 mole of hydrogen chloride was dissolved in distilled water and the volume made up of 0.50 dm3. If 15.0 cm3 of the solution requires 12.50 cm3 of aqueous sodium trioxocarbonate (IV) for neutralization, calculate the concentration of the alkaline solution
A
0.30 mol dm3
B
0.40 mol dm3
C
0.50 mol dm3
D
0.60 mol dm3
correct option: a
M1 V1 = M2 V2
∴ Mn Vn represent volume and molar concentration of HCL also MyVy represent volume and molar concentration of Na2CO3
MnVn = MyVy
0.25 * 15 = 12.50 * My
My = (0.25 * 15)/12.50
My = 0.3m/dm3
Users' Answers & Comments∴ Mn Vn represent volume and molar concentration of HCL also MyVy represent volume and molar concentration of Na2CO3
MnVn = MyVy
0.25 * 15 = 12.50 * My
My = (0.25 * 15)/12.50
My = 0.3m/dm3
15
The correct order of increasing oxidation number of the transition metal ions for the compounds K2Cr2O7, V2O5 and KMnO4 is
A
V2O5 < K2Cr2O7 < KMnO4
B
K2Cr2O7 < KMnO4 < V2O5
C
KMnO4 < K2Cr2O7 < V2O5
D
KMnO4 < V2O5 < K2Cr2O7
correct option: a
Users' Answers & Comments16
The set of pollutants that is most likely to be produced when petrol is accidentally spilled on plastic materials and ignited is
A
CO, CO2 and SO2
B
CO, HCL and SO2
C
CO, CO2 and HCL
D
SO2, CO2 and HCL
correct option: b
Users' Answers & Comments17
What is observed when aqueous solutions of each of tetraoxosulphate (VI) acid, potassium trioxoiodate (V) and potassium iodide are mixed together?
A
A white precipitate is formed
B
A green precipitate is formed
C
The mixture remains colourless
D
The mixture turns reddish brown
correct option: d
Users' Answers & Comments18
The solution with the lowest pH value is
A
5 ml of (m/10) HCL
B
10 ml of (m/10) HCL
C
15 ml of (m/5) HCL
D
20 ml of (m/8) HCL
correct option: a
Users' Answers & Comments19
The solubility product of Cu(IO3)2 is 1.08 * 10-7. Assuming that neither ions react appreciable with water to form H+ and OH-, what is the solubility of this salt?
A
2.7 * 10-8 mol dm-3
B
9.0 * 10-8 mol dm-3
C
3.0 * 10-3 mol dm-3
D
9.0 * 10-3 mol dm-3
correct option: d
Users' Answers & Comments20
The entropy and enthalpy of a system are a measure of
A
degree of disorderlinesss and heat content respectively
B
heat content and degree of disorderliness respectively
C
heat content of a system only
D
degree of disorderliness only
correct option: a
Users' Answers & Comments