1991 - JAMB Chemistry Past Questions and Answers - page 2
11
The ions X- and Y+ are isoelectronic, each containing a total of 10 electrons.
How many protons are in the nuclei of the neutral atoms of X and Y respectively?
How many protons are in the nuclei of the neutral atoms of X and Y respectively?
A
10 and 10
B
9 and 9
C
11 and 9
D
9 and 11
correct option: d
X- means one excess electron, hence 9 protons while Y +/- means one deficit electron hence 11 protons X and Y = 9 and 11
Users' Answers & Comments12
Which of the following represents the type of bonding present in ammonium chloride molecule?
A
Ionic only
B
Covalent only
C
Ionic and dative covalent
D
Dative covalent only
correct option: c
Users' Answers & Comments13
Which of the following is arranged in order of increasing electronegativity?
A
Chlorine, aluminium, magnesium, phosphorus, sodium
B
sodium, magnesium, aluminium, phosphorus, chlorine
C
Chlorine, phosphorus, phosphorous, aluminium, magnesium, sodium
D
Sodium, chlorine, phosphorus, magnesium, aluminium
correct option: b
Users' Answers & Comments14
A quantity of air was passed through a weighed amount of alkaline pyrogallol. An increase in the weight of the pyrogallol would result from the absorption of?
A
nitrogen
B
neon
C
argon
D
oxygen
15
Which of the following ions is a pollutant in drinking water even in trace amounts?
A
Ca2+
B
Hg2+
C
Mg2+
D
Fe2+
correct option: b
Users' Answers & Comments16
The solubility of copper (II) tetraoxosulphate (Iv) is 75g in 100g of water at 100°C and 25g in 100g of water at 30°C. What mass of the salt would crystallize, if 50g of copper (II) tetraoxosulphate (VI) solution saturated at 100°C were cooled to 30°C ?
A
57.5
B
42.2
C
28.6
D
14.3
correct option: d
solute + solvent = solution
at 100oC; 75g + 100g = 175g
at30oC; \(\frac{25g}{50g}\) + 100g = 125g
From 100oC - 30oC; 175g CuSO4 ppt 50g
From 100oC - 30oC; 50g CuSO4 ppt \(\frac{50 \times 50}{175}\) = 14.3
Users' Answers & Commentsat 100oC; 75g + 100g = 175g
at30oC; \(\frac{25g}{50g}\) + 100g = 125g
From 100oC - 30oC; 175g CuSO4 ppt 50g
From 100oC - 30oC; 50g CuSO4 ppt \(\frac{50 \times 50}{175}\) = 14.3
17
A sample of temporary hard water can be prepared in the laboratory by?
A
disolving calcium chloride in distilled water
B
saturating lime water with carbon (IV) oxide
C
saturating distilled water with calcium hydroxide
D
dissolving sodium hydrogen trioxocarbonate (IV) in some distilled water
correct option: b
Users' Answers & Comments18
A property of a colloidal dispersion which a solution does not have is?
A
the Tyndall effect
B
homogeneity
C
osmotic pressure
D
surface polarity
correct option: a
Users' Answers & Comments19
50 cm3 of sulphur (IV) oxide, 800 cm3 of ammonia, 450 cm3 of hydrogen chloride, 1.0 cm3 of at 15°C. Which of the following is suitable for demonstrating the fountain experiment?
A
Sulphur (IV) oxide hydrogen chloride
B
Carbon (IV) oxide and amonia
C
Amonia and hydrogen chloride
D
Carbon (IV) oxide and surphur (IV) oxide
correct option: c
Users' Answers & Comments20
How many structural isomers can be written for the alkyl bromide, C4H9Br?
A
3
B
4
C
6
D
8
correct option: b
Users' Answers & Comments