BS Bachelor of Science: Life, Physical, and Chemical 4 — Questions and Answers
Question 1: What is the oxidation state of sulfur in H₂SO₄ (sulfuric acid)?
- +2
- +4
- +6 (Correct answer)
- +8
Correct answer: +6
In H₂SO₄, with H at +1 and O at -2, sulfur must be +6 to balance the overall neutral charge.
Question 2: Which type of chemical reaction involves one element replacing another element in a compound?
- Synthesis
- Decomposition
- Single displacement (Correct answer)
- Double displacement
Correct answer: Single displacement
In a single displacement reaction, a more reactive element displaces a less reactive element from a compound.
Question 3: According to Le Chatelier's principle, increasing pressure on a gaseous equilibrium will shift the reaction 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
Increased pressure shifts equilibrium toward the side with fewer moles of gas to reduce the pressure.
Question 4: Which quantum number describes the shape of an atomic orbital?
- Principal quantum number (n)
- Angular momentum quantum number (l) (Correct answer)
- Magnetic quantum number (mₗ)
- Spin quantum number (mₛ)
Correct answer: Angular momentum quantum number (l)
The angular momentum quantum number (l) determines the shape of the orbital (s, p, d, or f).
Question 5: A buffer solution resists changes in pH by containing which combination of components?
- A strong acid and its conjugate base
- A weak acid and its conjugate base (Correct answer)
- Two strong bases
- Water and a neutral salt
Correct answer: A weak acid and its conjugate base
A buffer contains a weak acid and its conjugate base (or weak base and conjugate acid), which neutralize added acid or base.
Question 6: Which intermolecular force is responsible for the unusually high boiling point of water compared to similar-sized molecules?
- London dispersion forces
- Dipole-dipole interactions
- Hydrogen bonding (Correct answer)
- Ionic interactions
Correct answer: Hydrogen bonding
Hydrogen bonding between water molecules requires more energy to break, raising water's boiling point significantly.
Question 7: In organic chemistry, what functional group is present in all alcohols?
- Carbonyl group (C=O)
- Carboxyl group (-COOH)
- Hydroxyl group (-OH) (Correct answer)
- Amino group (-NH₂)
Correct answer: Hydroxyl group (-OH)
Alcohols are defined by the presence of one or more hydroxyl (-OH) groups attached to a carbon atom.
BS Bachelor of Science: Life, Physical, and Chemical 4
What is the oxidation state of sulfur in H₂SO₄ (sulfuric acid)?