POST UTME WELLSPRING UNIVERSITY 2020 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 10 mL sample of a solution containing 0.5 M NaCl is added to a 20 mL sample of a solution containing 0.2 M AgNO3. What is the concentration of the resulting solution?
A. 0.1 M
B. 0.2 M
C. 0.3 M
D. 0.4 M
Question 2
A solution of HCl is titrated with a solution of NaOH. If 25 mL of 0.1 M HCl is required to neutralize 20 mL of 0.2 M NaOH, what is the concentration of the HCl solution?
A. 0.05 M
B. 0.1 M
C. 0.15 M
D. 0.2 M
Question 3
A solution of 0.0500 M HCl is titrated with 0.100 M NaOH. What is the pH of the solution after 50.0 mL of NaOH has been added?
A. 2.00
B. 3.00
C. 4.00
D. 5.00
Question 4
A solution contains 2.5 g of NaCl per 100 mL of solution. What is the molarity of the solution?
A. 0.1 M
B. 0.2 M
C. 0.5 M
D. 1.0 M
Question 5
A 2.0 L sample of a solution containing 0.2 M NaOH is titrated with 0.2 M HCl. Calculate the pH of the solution after the addition of 10 mL of HCl.
A. 1.0
B. 2.0
C. 3.0
D. 4.0
Question 6
A 2.50 g sample of a compound containing only carbon and hydrogen is analyzed by combustion. The resulting CO2 and H2O are collected and weighed. If the mass of CO2 is 1.25 g and the mass of H2O is 0.750 g, what is the empirical formula of the compound?
A. CH2
B. C2H4
C. C3H6
D. C4H8
Question 7
A solution contains 0.1 M HCl and 0.2 M NaOH. What is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 8
Determine the number of moles of ethene (C2H4) produced when 2.5 g of C2H4 is decomposed at 25°C and 1 atm. The molar mass of C2H4 is 28 g/mol. The decomposition reaction is: C2H4 → C2H2 + H2.
A. 0.089 mol
B. 0.0895 mol
C. 0.090 mol
D. 0.091 mol
Question 9
A diagram of a titration setup is shown below. If the burette contains 0.1 M NaOH and the flask contains 25 mL of 0.2 M HCl, what is the concentration of the NaOH solution?
A. 0.05 M
B. 0.1 M
C. 0.15 M
D. 0.2 M
Question 10
A sample of gas occupies a volume of 2.5 L at a temperature of 298 K and pressure of 1.2 atm. If the temperature is increased to 323 K while keeping the pressure cons\tant, what is the new volume of the gas?
A. 3.2 L
B. 3.5 L
C. 3.8 L
D. 4.1 L
Question 11
The rate cons\tant (k) for a first-order reaction is given by the equation: k = Ae^\( -Ea/RT \). If the activation energy (Ea) is 100 kJ/mol, the gas cons\tant (R) is 8.314 J/\( mol*K \), and the temperature (T) is 300 K, what is the value of the rate cons\tant (k) if the pre-exponential factor (A) is 1.0 x 10^10 s^\( -1 \)?
A. 1.0 x 10^\( -5 \) s^\( -1 \)
B. 1.0 x 10^\( -3 \) s^\( -1 \)
C. 1.0 x 10^\( -2 \) s^\( -1 \)
D. 1.0 x 10^\( -1 \) s^\( -1 \)
Question 12
A sample of nitrogen gas is collected over water at a temperature of 25°C and a pressure of 1 atm. If the partial pressure of water vapor is 0.02 atm, what is the mole \fraction of nitrogen gas?
A. 0.98
B. 0.99
C. 0.995
D. 0.999
Question 13
A diagram of a periodic table is shown below. Which element has the atomic number 12?
A. Mg
B. Ca
C. K
D. Na
Question 14
A solution contains 0.1 M HCl and 0.1 M NaOH. What is the pH of the solution?
A. 1.0
B. 2.0
C. 3.0
D. 4.0
Question 15
A solution of 0.100 M HCl is titrated with 0.0500 M NaOH. What is the pH of the solution after 25.0 mL of NaOH has been added?
A. 2.00
B. 3.00
C. 4.00
D. 5.00

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: