CHEM 1020 FINAL EXAM| 184 QUESTIONS| WITH
COMPLETE SOLUTIONS
Course
CHEM 1020
Question 1
Which of the following represents an endothermic reaction?
A) CaCO3(s)→CaO(s)+CO2(g)\text{CaCO}_3 (s) \rightarrow \text{CaO} (s) + \text{CO}_2
(g)CaCO3(s)→CaO(s)+CO2(g)
B) H2(g)+12O2(g)→H2O(l)+heat\text{H}_2 (g) + \frac{1}{2} \text{O}_2 (g) \rightarrow \
text{H}_2\text{O} (l) + \text{heat}H2(g)+21O2(g)→H2O(l)+heat
C) NH4Cl(s)+heat→NH3(g)+HCl(g)\text{NH}_4\text{Cl} (s) + \text{heat} \rightarrow \
text{NH}_3 (g) + \text{HCl} (g)NH4Cl(s)+heat→NH3(g)+HCl(g)
D) CH4(g)+2O2(g)→CO2(g)+2H2O(g)+heat\text{CH}_4 (g) + 2 \text{O}_2 (g) \
rightarrow \text{CO}_2 (g) + 2 \text{H}_2\text{O} (g) + \text{heat}CH4(g)+2O2(g)→CO2
(g)+2H2O(g)+heat
Answer: C) NH4Cl(s)+heat→NH3(g)+HCl(g)\text{NH}_4\text{Cl} (s) + \text{heat} \
rightarrow \text{NH}_3 (g) + \text{HCl} (g)NH4Cl(s)+heat→NH3(g)+HCl(g)
Rationale: An endothermic reaction absorbs heat from the surroundings. In this reaction,
heat is required to convert solid ammonium chloride into ammonia gas and hydrochloric acid.
Question 2
What is the pH of a solution with a hydrogen ion concentration of 1.0×10−3 M1.0 \times
10^{-3} \, \text{M}1.0×10−3M?
A) 1
B) 3
C) 7
D) 10
Answer: B) 3
Rationale: pH is calculated using the formula pH=−log[H+]\text{pH} = -\log[\
text{H}^+]pH=−log[H+]. For a hydrogen ion concentration of 1.0×10−3 M1.0 \times 10^{-
3} \, \text{M}1.0×10−3M, the pH is −log(1.0×10−3)=3 -\log(1.0 \times 10^{-3}) =
3−log(1.0×10−3)=3.
Question 3
Which of the following statements about catalysts is true?
A) They increase the activation energy of a reaction.
B) They are consumed in the reaction.
,C) They provide an alternate pathway with a lower activation energy.
D) They change the equilibrium constant of the reaction.
Answer: C) They provide an alternate pathway with a lower activation energy.
Rationale: Catalysts lower the activation energy, allowing the reaction to proceed more
quickly without being consumed in the process or changing the equilibrium constant.
Question 4
What is the molarity of a solution prepared by dissolving 10 grams of sodium chloride
(NaCl) in enough water to make 0.5 liters of solution? (Molar mass of NaCl = 58.44
g/mol)
A) 0.34 M
B) 0.86 M
C) 1.00 M
D) 1.71 M
Answer: B) 0.34 M
Rationale: First, calculate the number of moles of NaCl:
Moles of NaCl=10 g58.44 g/mol=0.171 mol\text{Moles of NaCl} = \frac{10 \, \text{g}}
{58.44 \, \text{g/mol}} = 0.171 \, \text{mol}Moles of NaCl=58.44g/mol10g=0.171mol
Then, calculate the molarity:
Molarity=0.171 mol0.5 L=0.342 M≈0.34 M\text{Molarity} = \frac{0.171 \, \text{mol}}{0.5 \,
\text{L}} = 0.342 \, \text{M} \approx 0.34 \, \text{M}Molarity=0.5L0.171mol
=0.342M≈0.34M
Question 5
Which type of bond involves the sharing of electron pairs between atoms?
A) Ionic bond
B) Metallic bond
C) Covalent bond
D) Hydrogen bond
Answer: C) Covalent bond
Rationale: Covalent bonds are formed when two atoms share one or more pairs of electrons,
allowing them to achieve stability in their outer electron shells.
Question 6
What is the empirical formula for a compound with the molecular formula C6H12O6\
text{C}_6\text{H}_{12}\text{O}_6C6H12O6?
A) C₁H₂O
B) C₂H₄O₂
, C) C₃H₆O₃
D) C₆H₁₂O₆
Answer: A) C₁H₂O
Rationale: The empirical formula is the simplest whole-number ratio of the elements in a
compound. For C6H12O6\text{C}_6\text{H}_{12}\text{O}_6C6H12O6, the ratio of C:H
is 1:2:1.
Question 7
Which of the following elements is most likely to form a cation with a +2 charge?
A) Sodium (Na)
B) Magnesium (Mg)
C) Aluminum (Al)
D) Potassium (K)
Answer: B) Magnesium (Mg)
Rationale: Magnesium is in Group 2 of the periodic table and typically loses two electrons to
achieve a stable electron configuration, forming a Mg2+\text{Mg}^{2+}Mg2+ cation.
Question 8
According to the ideal gas law, what is the relationship between pressure (P), volume
(V), temperature (T), and the number of moles (n) of a gas?
A) PV=nRTPV = nRTPV=nRT
B) P+V=nRTP + V = nRTP+V=nRT
C) PVT=nRPVT = nRPVT=nR
D) P=nRT/VP = nRT/VP=nRT/V
Answer: A) PV=nRTPV = nRTPV=nRT
Rationale: The ideal gas law states that the product of the pressure and volume of a gas is
equal to the product of the number of moles, the ideal gas constant (R), and the absolute
temperature.
Question 9
What is the primary intermolecular force present in water (H₂O)?
A) Dispersion forces
B) Dipole-dipole interactions
C) Hydrogen bonding
D) Ionic bonding
Answer: C) Hydrogen bonding
Rationale: Water molecules exhibit strong hydrogen bonding due to the presence of
COMPLETE SOLUTIONS
Course
CHEM 1020
Question 1
Which of the following represents an endothermic reaction?
A) CaCO3(s)→CaO(s)+CO2(g)\text{CaCO}_3 (s) \rightarrow \text{CaO} (s) + \text{CO}_2
(g)CaCO3(s)→CaO(s)+CO2(g)
B) H2(g)+12O2(g)→H2O(l)+heat\text{H}_2 (g) + \frac{1}{2} \text{O}_2 (g) \rightarrow \
text{H}_2\text{O} (l) + \text{heat}H2(g)+21O2(g)→H2O(l)+heat
C) NH4Cl(s)+heat→NH3(g)+HCl(g)\text{NH}_4\text{Cl} (s) + \text{heat} \rightarrow \
text{NH}_3 (g) + \text{HCl} (g)NH4Cl(s)+heat→NH3(g)+HCl(g)
D) CH4(g)+2O2(g)→CO2(g)+2H2O(g)+heat\text{CH}_4 (g) + 2 \text{O}_2 (g) \
rightarrow \text{CO}_2 (g) + 2 \text{H}_2\text{O} (g) + \text{heat}CH4(g)+2O2(g)→CO2
(g)+2H2O(g)+heat
Answer: C) NH4Cl(s)+heat→NH3(g)+HCl(g)\text{NH}_4\text{Cl} (s) + \text{heat} \
rightarrow \text{NH}_3 (g) + \text{HCl} (g)NH4Cl(s)+heat→NH3(g)+HCl(g)
Rationale: An endothermic reaction absorbs heat from the surroundings. In this reaction,
heat is required to convert solid ammonium chloride into ammonia gas and hydrochloric acid.
Question 2
What is the pH of a solution with a hydrogen ion concentration of 1.0×10−3 M1.0 \times
10^{-3} \, \text{M}1.0×10−3M?
A) 1
B) 3
C) 7
D) 10
Answer: B) 3
Rationale: pH is calculated using the formula pH=−log[H+]\text{pH} = -\log[\
text{H}^+]pH=−log[H+]. For a hydrogen ion concentration of 1.0×10−3 M1.0 \times 10^{-
3} \, \text{M}1.0×10−3M, the pH is −log(1.0×10−3)=3 -\log(1.0 \times 10^{-3}) =
3−log(1.0×10−3)=3.
Question 3
Which of the following statements about catalysts is true?
A) They increase the activation energy of a reaction.
B) They are consumed in the reaction.
,C) They provide an alternate pathway with a lower activation energy.
D) They change the equilibrium constant of the reaction.
Answer: C) They provide an alternate pathway with a lower activation energy.
Rationale: Catalysts lower the activation energy, allowing the reaction to proceed more
quickly without being consumed in the process or changing the equilibrium constant.
Question 4
What is the molarity of a solution prepared by dissolving 10 grams of sodium chloride
(NaCl) in enough water to make 0.5 liters of solution? (Molar mass of NaCl = 58.44
g/mol)
A) 0.34 M
B) 0.86 M
C) 1.00 M
D) 1.71 M
Answer: B) 0.34 M
Rationale: First, calculate the number of moles of NaCl:
Moles of NaCl=10 g58.44 g/mol=0.171 mol\text{Moles of NaCl} = \frac{10 \, \text{g}}
{58.44 \, \text{g/mol}} = 0.171 \, \text{mol}Moles of NaCl=58.44g/mol10g=0.171mol
Then, calculate the molarity:
Molarity=0.171 mol0.5 L=0.342 M≈0.34 M\text{Molarity} = \frac{0.171 \, \text{mol}}{0.5 \,
\text{L}} = 0.342 \, \text{M} \approx 0.34 \, \text{M}Molarity=0.5L0.171mol
=0.342M≈0.34M
Question 5
Which type of bond involves the sharing of electron pairs between atoms?
A) Ionic bond
B) Metallic bond
C) Covalent bond
D) Hydrogen bond
Answer: C) Covalent bond
Rationale: Covalent bonds are formed when two atoms share one or more pairs of electrons,
allowing them to achieve stability in their outer electron shells.
Question 6
What is the empirical formula for a compound with the molecular formula C6H12O6\
text{C}_6\text{H}_{12}\text{O}_6C6H12O6?
A) C₁H₂O
B) C₂H₄O₂
, C) C₃H₆O₃
D) C₆H₁₂O₆
Answer: A) C₁H₂O
Rationale: The empirical formula is the simplest whole-number ratio of the elements in a
compound. For C6H12O6\text{C}_6\text{H}_{12}\text{O}_6C6H12O6, the ratio of C:H
is 1:2:1.
Question 7
Which of the following elements is most likely to form a cation with a +2 charge?
A) Sodium (Na)
B) Magnesium (Mg)
C) Aluminum (Al)
D) Potassium (K)
Answer: B) Magnesium (Mg)
Rationale: Magnesium is in Group 2 of the periodic table and typically loses two electrons to
achieve a stable electron configuration, forming a Mg2+\text{Mg}^{2+}Mg2+ cation.
Question 8
According to the ideal gas law, what is the relationship between pressure (P), volume
(V), temperature (T), and the number of moles (n) of a gas?
A) PV=nRTPV = nRTPV=nRT
B) P+V=nRTP + V = nRTP+V=nRT
C) PVT=nRPVT = nRPVT=nR
D) P=nRT/VP = nRT/VP=nRT/V
Answer: A) PV=nRTPV = nRTPV=nRT
Rationale: The ideal gas law states that the product of the pressure and volume of a gas is
equal to the product of the number of moles, the ideal gas constant (R), and the absolute
temperature.
Question 9
What is the primary intermolecular force present in water (H₂O)?
A) Dispersion forces
B) Dipole-dipole interactions
C) Hydrogen bonding
D) Ionic bonding
Answer: C) Hydrogen bonding
Rationale: Water molecules exhibit strong hydrogen bonding due to the presence of
