POST UTME RHEMA UNIVERSITY 2017 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 1.0 M solution of HCl is mixed with a 1.0 M solution of NaOH in a 1:1 ratio. What is the concentration of the resulting solution?
A. 0.5 M
B. 1.0 M
C. 2.0 M
D. 5.0 M
Question 2
The reaction 2H2(g) + O2(g) → 2H2O(l) has a rate cons\tant of 0.02 s^-1 at 298 K. If the activation energy is 120 kJ/mol, calculate the rate cons\tant at 323 K.
A. 0.04 s^-1
B. 0.06 s^-1
C. 0.08 s^-1
D. 0.10 s^-1
Question 3
A sample of an ideal gas is heated at cons\tant volume. Which of the following statements is true about the change in entropy?
A. Entropy increases
B. Entropy decreases
C. Entropy remains cons\tant
D. Entropy is undefined
Question 4
The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. Calculate the s\tandard enthalpy of combustion of 2.5 g of carbon at 298 K.
A. -987.5 kJ
B. -393.5 kJ
C. 393.5 kJ
D. 987.5 kJ
Question 5
A 2.5 M solution of HCl is mixed with a 2.5 M solution of NaOH. Calculate the number of moles of NaCl formed.
A. 0.5 mol
B. 1.0 mol
C. 1.5 mol
D. 2.0 mol
Question 6
A metal alloy is composed of 80% copper and 20% zinc. What is the empirical formula of the alloy?
A. Cu2Zn
B. CuZn
C. Cu3Zn2
D. CuZn2
Question 7
A 10 mL sample of a solution containing 0.1 M HCl is mixed with 10 mL of a solution containing 0.1 M NaOH. What is the pH of the resulting solution?
A. 1
B. 2
C. 3
D. 4
Question 8
A 10.0 g sample of a metal is heated in a crucible until it reaches a temperature of 1000°C. If the metal has a specific heat capacity of 0.1 J/g°C, what is the energy required to heat the metal to the desired temperature?
A. 1000 J
B. 10000 J
C. 100000 J
D. 1000000 J
Question 9
The reaction 2NO(g) + O2(g) → 2NO2(g) has a rate cons\tant of 0.05 s^-1 at 298 K. If the activation energy is 80 kJ/mol, calculate the rate cons\tant at 323 K.
A. 0.08 s^-1
B. 0.10 s^-1
C. 0.12 s^-1
D. 0.15 s^-1
Question 10
A 1.0 M solution of FeSO4 is electrolyzed at 298 K. Calculate the mass of Fe deposited at the cathode after 2 hours.
A. 0.5 g
B. 1.0 g
C. 1.5 g
D. 2.0 g
Question 11
A sample of an ideal gas at 25°C and 1 atm is heated to 50°C at cons\tant pressure. Calculate the new volume of the gas, given that the initial volume is 2.5 L.
A. 3.125 L
B. 4.166 L
C. 5.208 L
D. 6.25 L
Question 12
A solution contains 2.5 g of glu\cose (C6H12O6) per 100 mL of water. What is the molarity of the solution?
A. 0.1 M
B. 0.5 M
C. 1.0 M
D. 2.0 M
Question 13
A 0.1 M solution of a weak base, B, is titrated with 0.1 M HCl. If 25 mL of HCl is required to reach the equivalence point, what is the number of moles of B in 1 L of the solution?
A. 0.005 mol
B. 0.01 mol
C. 0.015 mol
D. 0.02 mol
Question 14
The half-life of a radioactive subs\tance is 5 years. If 100 g of the subs\tance initially decays to 50 g after 5 years, what is the decay cons\tant (λ) of the subs\tance?
A. 0.139 yr^{-1}
B. 0.139 yr^{-1}
C. 0.139 yr^{-1}
D. 0.139 yr^{-1}
Question 15
The reaction 2NO(g) + O2(g) → 2NO2(g) has a rate cons\tant of 0.05 s^-1 at 298 K. If the activation energy is 80 kJ/mol, calculate the rate cons\tant at 323 K.
A. 0.08 s^-1
B. 0.10 s^-1
C. 0.12 s^-1
D. 0.15 s^-1

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: