POST UTME BELLS UNIVERSITY 2023 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A $1.0\,\text{L}$ solution of $\text{NaOH}$ contains $0.15\,\text{M}$ $\text{NaOH}$. If $10\,\text{mL}$ of this solution is added to $100\,\text{mL}$ of $0.10\,\text{M}$ $\text{HCl}$, what is the concentration of $\text{OH}^{-}$ in the resulting solution?
A. $0.015\,\text{M}$
B. $0.030\,\text{M}$
C. $0.045\,\text{M}$
D. $0.060\,\text{M}$
Question 2
A polymer has a molecular weight of 100,000 g/mol. If the polymer is composed of 80% monomer A and 20% monomer B, what is the molecular weight of monomer A?
A. 80,000 g/mol
B. 100,000 g/mol
C. 120,000 g/mol
D. 140,000 g/mol
Question 3
A 5.00-mL sample of a solution containing 0.100 M NaOH is mixed with 10.0 mL of a solution containing 0.0500 M HCl. What is the concentration of OH- ions in the resulting solution?
A. 0.0250 M
B. 0.0500 M
C. 0.0750 M
D. 0.100 M
Question 4
The diagram below shows a setup for determining the rate cons\tant of a reaction. If the reaction is first-order with respect to the reac\tant, what is the relationship between the rate cons\tant and the slope of the plot?
A. $k = \text{slope}$
B. $k = \frac{1}{\text{slope}}$
C. $k = \text{slope}^2$
D. $k = \frac{1}{\text{slope}^2}$
Question 5
The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. The s\tandard enthalpy of formation of H2O(l) is -285.8 kJ/mol. Calculate the s\tandard enthalpy of formation of CH4(g).
A. -74.8 kJ/mol
B. -74.5 kJ/mol
C. -74.2 kJ/mol
D. -75.1 kJ/mol
Question 6
A metal has a density of 5.5 g/cm^3 and a molar mass of 55 g/mol. What is the volume of 2.5 mol of this metal?
A. 0.045 m^3
B. 0.045 L
C. 0.045 cm^3
D. 0.045 mL
Question 7
A 1 M solution of HNO3 is titrated with 1 M NaOH. If 50 mL of the acid is required to reach the equivalence point, what is the concentration of the acid?
A. 0.5 M
B. 1 M
C. 2 M
D. 4 M
Question 8
A 0.5 M solution of HCl is titrated with 1 M NaOH. If 50 mL of the acid is required to reach the equivalence point, what is the concentration of the acid?
A. 0.25 M
B. 0.5 M
C. 1 M
D. 2 M
Question 9
The s\tandard enthalpy of formation of NH3(g) is -45.9 kJ/mol. The s\tandard enthalpy of formation of H2O(l) is -285.8 kJ/mol. Calculate the s\tandard enthalpy of formation of NH4Cl(s).
A. -206.5 kJ/mol
B. -206.2 kJ/mol
C. -206.9 kJ/mol
D. -207.1 kJ/mol
Question 10
A diagram of a redox reaction is shown below. Identify the oxidizing agent.
A. Cell A
B. Cell B
C. Both cells
D. Neither cell
Question 11
What is the oxidation state of the underlined atom in the compound H_2SO_4?
A. +2
B. +4
C. +6
D. +8
Question 12
A 25 mL sample of a 0.5 M solution of sodium carbonate (Na2CO3) is titrated with a 1 M solution of hydrochloric acid (HCl). Calculate the number of moles of HCl required to reach the equivalence point.
A. 0.0125 mol
B. 0.025 mol
C. 0.0375 mol
D. 0.05 mol
Question 13
A 25.0-g sample of a solid is found to have a mass of 20.0 g when heated in a stream of oxygen gas. The mass of the carbon dioxide produced is 5.00 g. What is the empirical formula of the compound?
A. C2H4
B. C3H6
C. C4H8
D. C5H10
Question 14
The reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) is a classic example of a neutralization reaction. Write the balanced chemical equation for this reaction, including the state of each subs\tance.
A. HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l)
B. HCl (aq) + NaOH (aq) → NaCl (s) + H2O (l)
C. HCl (g) + NaOH (aq) → NaCl (aq) + H2O (l)
D. HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (g)
Question 15
What is the major product of the reaction between 2-methyl-2-butene and HBr?
A. CH_3CH\( Br)\( CH_3 \ \)CH_3
B. CH_3CH=CHCH_2Br
C. CH_3CH_2CH(Br)CH_3
D. CH_3CH_2CH_2CH_2Br

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: