POST UTME SKYLINE UNIVERSITY 2022 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A solution contains 0.1 M NaCl. If 10 mL of this solution is diluted to 100 mL, what is the concentration of the resulting solution?
A. 0.01 M
B. 0.05 M
C. 0.1 M
D. 0.2 M
Question 2
Determine the number of moles of electrons transferred in the electrolysis of 2.5 L of 0.5 M H2SO4.
A. 1 mole
B. 2 moles
C. 3 moles
D. 4 moles
Question 3
A sample of $\text{CO}_2$ gas occupies a volume of $2.50\,\text{L}$ at $25\,\text{\textdegree C}$ and $1.00\,\text{atm}$. Calculate the number of moles of $\text{CO}_2$ present.
A. 0.0500\,\text{mol}
B. 0.100\,\text{mol}
C. 0.200\,\text{mol}
D. 0.250\,\text{mol}
Question 4
A metal M has a s\tandard electrode potential of -0.5 V. If a cell is constructed with M as the cathode and a s\tandard hydrogen electrode as the anode, what is the cell potential?
A. +0.5 V
B. -0.5 V
C. +1.0 V
D. -1.0 V
Question 5
The atomic radius of an element is the dis\tance from the nucleus to the outermost electron in a neutral atom. What is the atomic radius of sodium (Na) in pm?
A. 186 pm
B. 190 pm
C. 194 pm
D. 198 pm
Question 6
The s\tandard enthalpy of formation of $\text{H}_2\text{O}\( \text{l} \)$ is $-285.8\,\text{kJ/mol}$. Calculate the s\tandard enthalpy of formation of $\text{H}_2\text{O}_2\( \text{l} \)$.
A. -285.8\,\text{kJ/mol}
B. -285.8\,\text{kJ/mol}+68.3\,\text{kJ/mol}
C. -285.8\,\text{kJ/mol}-68.3\,\text{kJ/mol}
D. -285.8\,\text{kJ/mol}+68.3\,\text{kJ/mol}+68.3\,\text{kJ/mol}
Question 7
A 2.5 g sample of a polymer is dissolved in 50 mL of a solvent. The solution has a vis\cosity of 0.8 Pa·s. What is the molecular weight of the polymer?
A. 1000 g/mol
B. 2000 g/mol
C. 5000 g/mol
D. 10,000 g/mol
Question 8
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 10^6 s^-1
B. 1.0 x 10^7 s^-1
C. 1.0 x 10^8 s^-1
D. 1.0 x 10^9 s^-1
Question 9
Determine the number of moles of $\text{CO}_2$ produced when 2.50 g of $\text{CaCO}_3$ is decomposed completely according to the equation $\text{CaCO}_3(s) \rightarrow \text{CaO}(s) + \text{CO}_2(g)$, given that the molar mass of $\text{CaCO}_3$ is 100.09 g/mol.
A. 0.0250 mol
B. 0.0500 mol
C. 0.0750 mol
D. 0.100 mol
Question 10
A 1.0 M solution of sodium carbonate (Na2CO3) is mixed with a 1.0 M solution of hydrochloric acid (HCl). What is the concentration of the resulting solution if the reaction is complete?
A. 0.5 M
B. 1.0 M
C. 1.5 M
D. 2.0 M
Question 11
The reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl) is a classic example of a neutralization reaction. What is the pH of the resulting solution after the reaction is complete?
A. 7
B. 10
C. 14
D. 12
Question 12
A 0.1 M solution of NaCl is prepared by dissolving 2.5 g of NaCl in 100 mL of water. What is the concentration of Na+ ions in the solution?
A. 0.05 M
B. 0.1 M
C. 0.2 M
D. 0.25 M
Question 13
A 2.00 g sample of a mixture containing $\text{NaCl}$ and $\text{KCl}$ is dissolved in water and the resulting solution is treated with $\text{AgNO}_3$ to form a precipitate of $\text{AgCl}$. If 1.50 g of $\text{AgCl}$ is obtained, calculate the mass percentage of $\text{NaCl}$ in the original mixture.
A. 20.0%
B. 30.0%
C. 40.0%
D. 50.0%
Question 14
A sample of $\text{H}_2$ gas occupies a volume of 2.50 L at a pressure of 1.00 atm and a temperature of 298 K. Calculate the number of moles of $\text{H}_2$ gas present, given that the ideal gas law is $PV = nRT$.
A. 0.0100 mol
B. 0.0200 mol
C. 0.0300 mol
D. 0.0400 mol
Question 15
A 10.0 g sample of an unknown hydrocarbon is burned in a bomb calorimeter, relea\sing 42.0 kJ of heat energy. What is the molar mass of the hydrocarbon if the heat of combustion is 42.0 kJ/g?
A. 100 g/mol
B. 200 g/mol
C. 300 g/mol
D. 400 g/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: