2014 - JAMB Chemistry Past Questions and Answers - page 2
11
The nitrogen obtained from air has a density higher than the one from nitrogen-containing compounds because the one from air is contaminated with
A
water vapour
B
oxgyen
C
rare gases
D
carbon (IV) oxide
correct option: c
Users' Answers & Comments12
Water is said to be temporarily hard when it contains
A
Ca (HCO3)2 and Mg (HCO3)2 salts
B
Ca (HCO3)2 and CaCO3 SALTS
C
Mg(HCO3)2 and CaSO4 salts
D
CaSO4 and Ca(HCO3)2 salts
correct option: a
Users' Answers & Comments13
On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as
A
efflorescence
B
diliquescence
C
hygroscopy
D
hydrolysis
correct option: a
Users' Answers & Comments14
16.55g of lead (ll) trioxonitrate (V) was dissolved in 100g of distilled water at 20oC, calculate the solubility of the solute in moldm-3
[Pb = 207, N = 14, O = 16]
[Pb = 207, N = 14, O = 16]
A
0.05 g
B
2.00 g
C
1.00 g
D
none of the above
correct option: d
molar mass of pb (N0 3) 2 = 331
Mole = \(\frac{16.55}{331}\)= 0.05 mole
∴0.05mole pb (No3)2 dissolved in 1000g H2O x = \(\frac{0.05x1000}{100}\)= 0.05 mole /dm 3
Users' Answers & CommentsMole = \(\frac{16.55}{331}\)= 0.05 mole
∴0.05mole pb (No3)2 dissolved in 1000g H2O x = \(\frac{0.05x1000}{100}\)= 0.05 mole /dm 3
15
The dispersion of a liquid in a liquid medium will give
A
an emulsion
B
a fog
C
a gel
D
an aerosol
correct option: a
Users' Answers & Comments16
The major and most effective way of controlling pollution is to
A
improve machinery so that the substances released from combustion are less harmful
B
pass strict laws against it by individuals and companies
C
educate people on the causes and effects of pollution
D
convert chemical wastes to harmless substances before releasing them into the environment
correct option: c
Users' Answers & Comments18
The colour of litmus in a neutral medium is
A
purple
B
pink
C
yellow
D
orange
correct option: a
Users' Answers & Comments19
The mathematical expression of PH is
A
log 10[OH-]
B
log 101/[H 3 O+]
C
log 10[H 3 O+]
D
log 101/[OH -]
correct option: b
Users' Answers & Comments20
Which of the following salts will turn blue litmus red?
A
Sodium tetrahydroxozincate (ll)
B
Potassium hydrogentetraoxosulphate (lV)
C
Sodium trioxocarbonate (lV)
D
Zinc chloride hydroxide
correct option: b
Users' Answers & Comments