POST UTME UNN 2020 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A solution contains 0.1 M NaCl and 0.2 M NaOH. What is the pH of the solution?
A. 1.0
B. 2.0
C. 3.0
D. 4.0
Question 2
A 0.5 M solution of NaOH is prepared by dissolving 25 g of NaOH in 1 L of water. Calculate the number of moles of NaOH used in preparing the solution.
A. 0.5 mol
B. 0.25 mol
C. 0.75 mol
D. 1.0 mol
Question 3
The s\tandard enthalpy of formation of CO2 is -393.5 kJ/mol. What is the s\tandard enthalpy of formation of CO?
A. -110.5 kJ/mol
B. -137.3 kJ/mol
C. -393.5 kJ/mol
D. -745.3 kJ/mol
Question 4
A polymer has a molecular weight of 100,000 g/mol and a degree of polymerization of 500. What is the molar mass of the repeating unit?
A. 200 g/mol
B. 400 g/mol
C. 500 g/mol
D. 1000 g/mol
Question 5
In a titration experiment, 25.0 mL of 0.100 M NaOH is added to 20.0 mL of 0.0500 M HCl. What is the pH of the resulting solution?
A. ( 1.00 )
B. ( 2.00 )
C. ( 3.00 )
D. ( 4.00 )
Question 6
A 5.0 L sample of a gas at 25°C and 2.0 atm is collected over water at 25°C. If the vapor pressure of water at 25°C is 0.031 atm, what is the partial pressure of the gas?
A. 1.969 atm
B. 1.969 kPa
C. 2.0 atm
D. 2.0 kPa
Question 7
A 2.5 g sample of a metal is dissolved in 25 mL of 0.1 M HCl. What is the concentration of the metal ion in the solution?
A. 0.01 M
B. 0.05 M
C. 0.1 M
D. 0.5 M
Question 8
A 2.00 M solution of HCl is prepared by dissolving 40.0 g of HCl in water and diluting to a total volume of 1.00 L. What is the concentration of HCl in the solution?
A. ( 1.00 ) M
B. ( 2.00 ) M
C. ( 3.00 ) M
D. ( 4.00 ) M
Question 9
A 10.0 g sample of a compound containing only carbon and hydrogen is analyzed and found to contain 6.0 g of carbon and 4.0 g of hydrogen. What is the empirical formula of the compound?
A. CH
B. C2H
C. C3H2
D. C4H3
Question 10
The following diagram shows a graph. What is the type of relationship between the variables?
A. Direct variation
B. Inverse variation
C. Proportional variation
D. Inverse square variation
Question 11
A 0.500 M solution of NaOH is prepared by dissolving 25.0 g of NaOH in water and diluting to a total volume of 1.00 L. What is the concentration of NaOH in the solution?
A. ( 0.250 ) M
B. ( 0.500 ) M
C. ( 0.750 ) M
D. ( 1.00 ) M
Question 12
A sample of a polymer has a molecular weight of 50,000 g/mol. If 0.5 g of the polymer is dissolved in 20 mL of solvent, what is the concentration of the solution in g/L?
A. 0.25 g/L
B. 0.5 g/L
C. 1.0 g/L
D. 2.0 g/L
Question 13
The reaction of cyclohexane with bromine in the presence of light produces a mixture of 1,2-dibromocyclohexane and 1,4-dibromocyclohexane. What is the major product of this reaction?
A. 1,2-dibromocyclohexane
B. 1,4-dibromocyclohexane
C. cis-1,2-dibromocyclohexane
D. trans-1,4-dibromocyclohexane
Question 14
A 1.5 g sample of a compound is found to have a mass of 2.5 g after being dried in an oven at 120°C. What is the mass of water in the compound?
A. 0.5 g
B. 1 g
C. 1.5 g
D. 2 g
Question 15
The s\tandard enthalpy of formation of NH3(g) is -45.9 kJ/mol. Calculate the s\tandard enthalpy of formation of N2(g) if the s\tandard enthalpy of formation of H2(g) is 0 kJ/mol.
A. 0 kJ/mol
B. 0 kJ/mol
C. 0 kJ/mol
D. 0 kJ/mol

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Help others prepare! Share this practice hub: