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\(^{-3}\) H\(_2\)SO\(_4\)
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 = \(\frac{MmIT}{96500n}\)
Where
M=mass
Mm = Molar mass = 64g/mol
I = current = 1.6A
T= Time =1h r=3600s
N= No of Charge = +2
M = \(\frac{64x \times 1.6 \times 3600}{96500 \times 2}\)
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
450cm\(^3\)
300cm\(^3\)
200cm\(^3\)
150cm\(^3\)
Correct answer is A
From the dilution law
C\(_1\)V\(_1\) = C\(_2\)V\(_2\)
C\(_1\) = Initial Concentration of NaOH = 0.6M
V\(_1\) = Initial Volume of NaOH = 300cm3
C\(_2\) = Final Concentration of NaOH = 0.4M
V\(_2\) = Final Volume of NaOH = ?
V\(_2\) = \(\frac{C_1V_1}{C_2}\)
V\(_2\) = \(\frac{0.6 \times 300}{0.4}\)
V\(_2\) = 450 cm\(^3\)
Correct Computation as it follows the equation specified