GACE Chemistry 2 — Questions and Answers
Question 1: Which type of chemical bond results from the electrostatic attraction between oppositely charged ions?
- Covalent bond
- Ionic bond (Correct answer)
- Hydrogen bond
- Metallic bond
Correct answer: Ionic bond
Ionic bonds form when one atom transfers electrons to another, creating oppositely charged ions that attract each other.
Question 2: A student dissolves 5.85 g of NaCl (molar mass 58.5 g/mol) in enough water to make 500 mL of solution. What is the molarity of the solution?
- 0.1 M
- 0.2 M (Correct answer)
- 0.5 M
- 1.0 M
Correct answer: 0.2 M
Moles of NaCl = 5.85/58.5 = 0.1 mol; Molarity = 0.1 mol / 0.5 L = 0.2 M.
Question 3: Which of the following best describes an exothermic reaction?
- The reaction absorbs heat from the surroundings
- The products have more energy than the reactants
- The reaction releases heat to the surroundings (Correct answer)
- The activation energy is zero
Correct answer: The reaction releases heat to the surroundings
Exothermic reactions release energy as heat, so the surroundings become warmer.
Question 4: What is the oxidation state of sulfur in H₂SO₄?
- +2
- +4
- +6 (Correct answer)
- -2
Correct answer: +6
Each H is +1, each O is −2; solving 2(+1) + S + 4(−2) = 0 gives S = +6.
Question 5: According to Le Chatelier's principle, what happens to the equilibrium position of N₂ + 3H₂ ⇌ 2NH₃ when pressure is increased?
- Shifts left, producing more reactants
- Shifts right, producing more NH₃ (Correct answer)
- Remains unchanged
- Increases the rate constant
Correct answer: Shifts right, producing more NH₃
Increasing pressure favors the side with fewer moles of gas; the right side has 2 moles vs. 4 on the left.
Question 6: Which subatomic particle determines the identity (atomic number) of an element?
- Neutron
- Electron
- Proton (Correct answer)
- Positron
Correct answer: Proton
The atomic number equals the number of protons, which uniquely identifies each element.
Question 7: What type of isomers have the same molecular formula and connectivity but differ in the spatial arrangement of atoms?
- Constitutional isomers
- Stereoisomers (Correct answer)
- Resonance structures
- Isotopes
Correct answer: Stereoisomers
Stereoisomers share the same connectivity but differ in the three-dimensional arrangement of their atoms in space.
GACE Chemistry 2
Which type of chemical bond results from the electrostatic attraction between oppositely charged ions?