POST UTME AL-HIKMAH UNIVERSITY 2019 Chemistry | Objective

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Question 1
A 2.5 M solution of sodium hydroxide (NaOH) is prepared by dissolving 25 g of NaOH in 1 L of water. What is the concentration of hydroxide ions \( OH- \) in the solution?
A. 0.05 M
B. 0.1 M
C. 0.25 M
D. 0.5 M
Question 2
A 1.0 M solution of H2SO4(aq) is mixed with a 2.0 M solution of NaOH(aq). What is the concentration of the resulting solution?
A. 1.0 M
B. 2.0 M
C. 3.0 M
D. 4.0 M
Question 3
The half-reaction for the reduction of Cu2+ to Cu is: Cu2+ + e- → Cu+ + H+.
A. Cu2+ + 2e- → Cu
B. Cu2+ + e- → Cu+ + H+
C. Cu2+ + 2e- → 2Cu
D. Cu2+ + e- → Cu
Question 4
A solution contains 0.1 M NaCl. If 10 mL of this solution is diluted to 100 mL, what is the concentration of the resulting solution?
A. 0.01 M
B. 0.1 M
C. 0.01 M
D. 0.001 M
Question 5
Calculate the s\tandard enthalpy of formation of CO2(g) from the following reaction: C(s) + O2(g) → CO2(g). The s\tandard enthalpies of formation of C(s) and O2(g) are -393.5 kJ/mol and 0 kJ/mol, respectively.
A. -393.5 kJ/mol
B. -393.5 kJ/mol + 0 kJ/mol
C. -393.5 kJ/mol + 0 kJ/mol + 0 kJ/mol
D. -393.5 kJ/mol + 0 kJ/mol + 0 kJ/mol + 0 kJ/mol
Question 6
The reaction of sodium metal with water is represented by the equation: 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g). What is the oxidation state of sodium in the product?
A. +1
B. +2
C. -1
D. -2
Question 7
Determine the IUPAC name of the following compound: CH3CH2CH2CH2CH3
A. Bu\tane
B. Pen\tane
C. Hexane
D. Hep\tane
Question 8
A 2.5 M solution of HCl(aq) is mixed with a 1.5 M solution of NaOH(aq). What is the concentration of the resulting solution?
A. 1.5 M
B. 2.5 M
C. 3.0 M
D. 4.0 M
Question 9
A 0.500 M solution of H2SO4 is titrated with 0.500 M NaOH. Calculate the pH of the solution after 25.0 mL of NaOH has been added.
A. 1.00
B. 2.00
C. 3.00
D. 4.00
Question 10
The diagram below shows a graph of the variation of the boiling point of a subs\tance with temperature. What is the type of variation represented by this graph?
A. Direct variation
B. Inverse variation
C. Proportional variation
D. Inverse square variation
Question 11
A solution of sodium chloride (NaCl) is prepared by dissolving 35.5 g of NaCl in 100 mL of water. The resulting solution has a density of 1.02 g/mL. Calculate the molarity of the solution.
A. 0.5 M
B. 1.0 M
C. 1.5 M
D. 2.0 M
Question 12
The s\tandard electrode potential of the Zn2+/Zn couple is -0.76 V. Calculate the s\tandard electrode potential of the Cu2+/Cu couple if the s\tandard electrode potential of the Cu2+/Cu couple is 0.34 V.
A. 0.10
B. 0.34
C. 0.50
D. 0.76
Question 13
A 0.1 M solution of HCl is mixed with a 0.1 M solution of NaOH. What is the resulting pH of the solution?
A. 1.0
B. 2.0
C. 3.0
D. 4.0
Question 14
The s\tandard electrode potential of the cell: Zn(s) | Zn2+(aq) | Cu2+(aq) | Cu(s) is 1.10 V. What is the s\tandard cell potential of the cell: Cu2+(aq) | Cu(s) | Zn2+(aq) | Zn(s)?
A. -1.10 V
B. -1.10 V
C. -1.10 V
D. 1.10 V
Question 15
Calculate the s\tandard enthalpy of formation of CaCO3(s) from the following data: ΔHf(CaO(s)) = -635.09 kJ/mol, ΔHf(CO2(g)) = -393.51 kJ/mol.
A. -1234.60 kJ/mol
B. -1234.60 kJ/mol
C. -1234.60 kJ/mol
D. -1234.60 kJ/mol

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