POST UTME LASU 2019 Chemistry | Objective

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Question 1
A metal (M) reacts with oxygen to form a metal oxide (MO). The balanced equation for the reaction is: 4M + 3O2 → 2MO. If 2.0 g of M is reacted with 1.0 L of O2 at STP, what is the limiting reac\tant?
A. M
B. O2
C. MO
D. Neither M nor O2 is the limiting reac\tant
Question 2
A solution contains 0.1 M HCl. If 10 mL of this solution is added to 100 mL of 0.1 M NaOH, what is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 3
A 0.1 M solution of a weak acid HA has a pH of 4.5. If 10 mL of 1 M NaOH is added to 20 mL of the acid solution, what is the pH of the resulting solution?
A. 3.5
B. 4.5
C. 5.5
D. 6.5
Question 4
A solution contains 0.1 M HCl. If 10 mL of this solution is added to 100 mL of 0.1 M NaOH, what is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 5
A 1.0 M solution of sulfuric acid (H2SO4) is titrated with a 2.0 M solution of sodium hydroxide (NaOH). If 20 mL of the acid solution is required to reach the equivalence point, calculate the number of moles of sulfuric acid (H2SO4) present in 30 mL of the solution.
A. 0.10
B. 0.15
C. 0.20
D. 0.25
Question 6
A metal M has a s\tandard electrode potential of +0.5 V. What is the s\tandard potential of the cell formed by depositing M at the cathode and oxidizing M at the anode?
A. -0.5 V
B. +0.5 V
C. +1 V
D. -1 V
Question 7
A diagram of a simple electrolytic cell is shown below. If the cell is operated at a cons\tant current of 2 A for 5 minutes, what is the mass of copper deposited at the cathode?
A. 0.12 g
B. 0.24 g
C. 0.36 g
D. 0.48 g
Question 8
A 2.0 M solution of H2SO4 is mixed with 2.0 M NaOH. Determine the pH of the resulting solution.
A. 1
B. 2
C. 3
D. 4
Question 9
A solution of HCl is electrolyzed u\sing a platinum electrode. What is the product at the cathode?
A. H2
B. Cl2
C. H2O
D. NaCl
Question 10
A 0.1 M solution of HCl is titrated with 0.1 M NaOH. At the equivalence point, the pH of the solution is 7. Determine the initial volume of HCl (in mL) required to reach the equivalence point.
A. 10 mL
B. 20 mL
C. 30 mL
D. 40 mL
Question 11
The electronegativity of an element in a compound is a measure of its ability to attract electrons towards itself. Which of the following elements has the highest electronegativity among the given options?
A. Fluorine (F)
B. Chlorine (Cl)
C. Bromine (Br)
D. Iodine (I)
Question 12
A sample of a non-metallic oxide has a molar mass of 120 g/mol. If 10.0 g of the oxide is decomposed, what is the volume of oxygen gas produced at STP?
A. 4.0 L
B. 6.0 L
C. 8.0 L
D. 10.0 L
Question 13
A metal (M) has a density of 10 g/cm^3. If a 2.0 g sample of M is dissolved in 100 mL of solvent, what is the concentration of the solution?
A. 0.1 M
B. 1.0 M
C. 10 M
D. 100 M
Question 14
A solution of 0.1 M \( H_2SO_4 \) is titrated with 0.1 M ( NaOH ). The pH of the solution at the equivalence point is 7. What is the initial volume of the acid solution in liters?
A. 0.1 L
B. 0.2 L
C. 0.5 L
D. 1 L
Question 15
A 2.0 M solution of sodium hydroxide (NaOH) is titrated with a 1.0 M solution of hydrochloric acid (HCl). If 25 mL of the acid solution is required to reach the equivalence point, calculate the number of moles of sodium hydroxide (NaOH) present in 50 mL of the solution.
A. 0.05
B. 0.10
C. 0.15
D. 0.20

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