EIT Chemistry 2 — Questions and Answers
Question 1: What is the oxidation state of sulfur in H₂SO₄?
- +2
- +4
- +6 (Correct answer)
- −2
Correct answer: +6
With H at +1×2 and O at −2×4, sulfur must be +6 to balance the neutral molecule.
Question 2: Le Chatelier's principle states that when a stress is applied to a system at equilibrium, the system will:
- Remain unchanged
- Shift to oppose the stress (Correct answer)
- Shift to enhance the stress
- Reach a new equilibrium randomly
Correct answer: Shift to oppose the stress
Le Chatelier's principle states the equilibrium shifts in the direction that counteracts the applied stress.
Question 3: The Henderson-Hasselbalch equation is primarily used to calculate:
- Reaction rate constants
- pH of a buffer solution (Correct answer)
- Gibbs free energy
- Equilibrium concentrations
Correct answer: pH of a buffer solution
pH = pKa + log([A⁻]/[HA]) is the Henderson-Hasselbalch equation for buffer pH.
Question 4: What is Avogadro's number?
- 6.022 × 10²³ (Correct answer)
- 6.626 × 10⁻³⁴
- 1.38 × 10⁻²³
- 9.81 × 10²³
Correct answer: 6.022 × 10²³
Avogadro's number is 6.022 × 10²³ entities per mole of substance.
Question 5: Which type of chemical bond involves the sharing of electrons between two atoms?
- Ionic bond
- Covalent bond (Correct answer)
- Metallic bond
- Hydrogen bond
Correct answer: Covalent bond
Covalent bonds form when atoms share electron pairs to achieve stable configurations.
Question 6: Raoult's Law describes which property of ideal solutions?
- Osmotic pressure
- Vapor pressure of a component (Correct answer)
- Boiling point elevation
- Freezing point depression
Correct answer: Vapor pressure of a component
Raoult's Law states that the partial vapor pressure equals the mole fraction times the pure-component vapor pressure.
EIT Chemistry 2
What is the oxidation state of sulfur in H₂SO₄?