POST UTME UI 2018 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
The atomic number of an element is equal to the number of ______ in its atomic nucleus.
A. protons
B. neutrons
C. electrons
D. photons
Question 2
A solution contains 0.1 M NaCl. What is the concentration of Cl- ions in the solution?
A. 0.05 M
B. 0.1 M
C. 0.2 M
D. 0.5 M
Question 3
A solution of 0.500 M HCl is mixed with a solution of 0.250 M NaOH. What is the concentration of the resulting solution?
A. 0.250 M
B. 0.500 M
C. 0.750 M
D. 1.000 M
Question 4
A sample of a gas occupies 2.5L at 25°C and 1.5 atm. What is the volume of the gas at 50°C and 3.0 atm?
A. 5.0L
B. 6.0L
C. 7.0L
D. 8.0L
Question 5
The s\tandard enthalpy of formation (ΔHf) of CO2(g) is -393.5 kJ/mol. Calculate the s\tandard enthalpy of combustion of 1.00 mol of C(s) to form CO2(g).
A. -393.5 kJ
B. -393.5 kJ/mol
C. -393.5 kJ/mol C
D. -393.5 kJ/mol CO2
Question 6
A 2.0g sample of a metal is heated in a crucible until it reaches a temperature of 1000°C. What is the energy required to heat the metal?
A. 200J
B. 300J
C. 400J
D. 500J
Question 7
A metal alloy is composed of 60% copper, 20% zinc, and 20% tin. If 500g of the alloy is melted and cast into a new shape, what is the mass of copper in the new shape?
A. 300g
B. 250g
C. 200g
D. 150g
Question 8
A 2.50-g sample of a metal carbonate is heated to produce a metal oxide and carbon dioxide gas. If the mass of the metal oxide produced is 1.75 g, what is the percentage yield of the reaction?
A. 60%
B. 70%
C. 80%
D. 90%
Question 9
The polymerization of styrene to polystyrene is an example of a ______ reaction.
A. chain-growth
B. step-growth
C. condensation
D. addition
Question 10
Determine the number of unpaired electrons in the ground state of the chromium ion, Cr3+.
A. 0
B. 1
C. 2
D. 3
Question 11
A 2.00-g sample of a metal is heated in air to produce a metal oxide. If the mass of the metal oxide produced is 2.50 g, what is the percentage increase in mass?
A. 25%
B. 50%
C. 75%
D. 100%
Question 12
A solution contains 2.5g of NaCl per 100mL of solution. What is the molarity of the solution?
A. 0.04M
B. 0.06M
C. 0.08M
D. 0.10M
Question 13
The half-life of a radioactive subs\tance is 5 years. If the initial amount of the subs\tance is 100 g, what is the amount remaining after 10 years?
A. 25 g
B. 50 g
C. 75 g
D. 100 g
Question 14
A 2.50 g sample of a subs\tance is found to have a mass of 2.50 g when placed in a 100 mL beaker. What is the density of the subs\tance?
A. 1.00
B. 1.50
C. 2.00
D. 2.50
Question 15
A 2.00 L flask contains a gas at 2.00 atm and 25°C. What is the pressure of the gas in a 1.00 L flask at 25°C?
A. 1.00 atm
B. 2.00 atm
C. 3.00 atm
D. 4.00 atm

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