IB Chemistry 2 — Questions and Answers
Question 1: Which type of bond results from the electrostatic attraction between oppositely charged ions?
- Covalent bond
- Metallic bond
- Ionic bond (Correct answer)
- Hydrogen bond
Correct answer: Ionic bond
An ionic bond forms when electrons are transferred from one atom to another, creating oppositely charged ions that attract each other.
Question 2: What is the oxidation state of sulfur in H₂SO₄?
- +4
- +6 (Correct answer)
- +2
- -2
Correct answer: +6
In H₂SO₄, hydrogen is +1 (×2) and oxygen is -2 (×4), so sulfur must be +6 for the molecule to be neutral.
Question 3: According to Le Chatelier's principle, increasing pressure on a gaseous equilibrium will shift the equilibrium toward the side with:
- More moles of gas
- Fewer moles of gas (Correct answer)
- Higher temperature
- Lower activation energy
Correct answer: Fewer moles of gas
Increasing pressure shifts equilibrium toward the side with fewer moles of gas to reduce the pressure.
Question 4: Which functional group is characteristic of aldehydes?
- -OH
- -COOH
- -CHO (Correct answer)
- -CO-
Correct answer: -CHO
Aldehydes contain the –CHO group, where the carbonyl carbon is bonded to at least one hydrogen atom.
Question 5: What does a negative ΔG value indicate about a chemical reaction?
- The reaction is endothermic
- The reaction is non-spontaneous
- The reaction is spontaneous (Correct answer)
- The reaction requires a catalyst
Correct answer: The reaction is spontaneous
A negative Gibbs free energy change (ΔG < 0) means the reaction is thermodynamically spontaneous under the given conditions.
Question 6: In an electrochemical cell, oxidation occurs at which electrode?
- Cathode
- Anode (Correct answer)
- Salt bridge
- Both electrodes equally
Correct answer: Anode
Oxidation (loss of electrons) always occurs at the anode, while reduction (gain of electrons) occurs at the cathode.
Question 7: Which quantum number describes the shape of an atomic orbital?
- Principal quantum number (n)
- Azimuthal quantum number (l) (Correct answer)
- Magnetic quantum number (mₗ)
- Spin quantum number (mₛ)
Correct answer: Azimuthal quantum number (l)
The azimuthal (angular momentum) quantum number l determines the shape of an orbital (s, p, d, or f).
IB Chemistry 2
Which type of bond results from the electrostatic attraction between oppositely charged ions?