Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
Calculate the pH of 0.05 moldm−3 H2SO4
1.30
1.12
1.00
0.30
Correct answer is C
Recall from pH formula pH = -Log [H+]
H2SO4 → 2H+ + SO42-
2H+ → 2 X0.05 = 0.1
pH= -Log [0.1] = 1
7.64g
3.82g
1.91g
0.96g
Correct answer is C
M = MmIT96500n
Where
M=mass
Mm = Molar mass = 64g/mol
I = current = 1.6A
T= Time =1h r=3600s
N= No of Charge = +2
M = 64x×1.6×360096500×2
M=1.91g
The solubility of the solids that dissolves in a given solvent with the liberation of heat will
increase with an increase in temperature
decrease with an increase in temperature
decrease with a decrease in temperature
not be affected by changes in temperature
Correct answer is B
Increasing temperature in exothermic reaction favors the left/reactant side and decreasing temperature will favor the right/product side.
Diamond is a bad conductor of electricity because its bonding electrons are used in
crystal lattice formation
covalent bond formation
metallic bond formation
coordinate bond formation
Correct answer is B
Diamond is a covalent macromolecule, and typical of a covalent substance is an insulator. All valence electrons are localized in well-defined covalent bonds and hence are not free to move through the structure
To what volume must 300cm3 of 0.60M sodium hydroxide solution be diluted to give a 0.40M solution?
450cm3
300cm3
200cm3
150cm3
Correct answer is A
From the dilution law
C1V1 = C2V2
C1 = Initial Concentration of NaOH = 0.6M
V1 = Initial Volume of NaOH = 300cm3
C2 = Final Concentration of NaOH = 0.4M
V2 = Final Volume of NaOH = ?
V2 = C1V1C2
V2 = 0.6×3000.4
V2 = 450 cm3
Correct Computation as it follows the equation specified