1. Stark-Einstein studied which aspect of photochemical reactions by applying the quantum theory of light?
(A) Qualitative
(B) Geometrical
(C) Quantitative
(D) Both Qualitative and Quantitative
2. When a beam of light passes through a transparent medium, the rate of decrease of intensity with the thickness of the medium is:
(A) Inversely proportional
(B) Equal
(C) Directly proportional
(D) Not related
3. A resonance effect is also known as:
(A) Mesomeric effect
(B) Electromeric effect
(C) Inductive effect
(D) Inductomeric effect
4. The Phenyl group shows which type of effect?
(A) –M effect
(B) +E effect
(C) +I effect
(D) +M effect
5. Greater the number of resonating structures for a given intermediate, ______ will be its stability.
(A) Less
(B) Not affected
(C) More
(D) No effect
6. When is the Beer-Lambert law applicable?
(A) If temperature changes
(B) If temperature varies linearly
(C) If non-monochromatic radiation is used
(D) If a dilute solution is used
7. In the mesomeric effect, electrons are transferred from:
(A) A multiple bond to an atom
(B) An atom with a lone pair to the adjacent single covalent bond
(C) A multiple bond to a single covalent bond
(D) All of the above
8. In photochemistry, which component of light causes a chemical reaction in a cell?
(A) Transmitted
(B) Adsorbed
(C) Absorbed
(D) Reflected
9. Which of the following is a correct statement about benzene?
(A) All the bond lengths in a benzene ring are equal due to resonance
(B) All the bond lengths are equal due to hyperconjugation
(C) Benzene has alternating single and double bond lengths
(D) All of the above
10. Which of the following is also known as the Principle of Photochemical Activation?
(A) Stark law
(B) Lambert’s law
(C) Draper law
(D) Grothus–Draper law
11. The phenomenon where two or more structures with identical atom positions are possible is called:
(A) Conjugation
(B) Hyperconjugation
(C) Resonance
(D) Vibration
12. Resonance energy is defined as the difference in energy between:
(A) Two consecutive resonating structures
(B) Resonance hybrid and the most stable resonating structure
(C) Resonance hybrid and the most unstable structure
(D) First and last resonating structures
13. Which of the following statements is incorrect?
(A) The actual structure lies between the resonating structures
(B) Resonating structures help describe molecules
(C) Resonating structures have real existence
(D) None of the above
14. True or False: The dipole moment of CH₃–CH₂–Cl is greater than CH₂=CH–Cl.
(A) False
(B) True
Answer: (B) True
15. The mesomeric effect influences:
(A) Dipole moment
(B) Strength of acids and bases
(C) Bond length
(D) All of the above
16. The Grothus–Draper law is of what nature?
(A) Quantitative
(B) Purely qualitative
(C) Both Qualitative and Quantitative
(D) Not acceptable
17. Which of the following is also called the Principle of Quantum Activation?
(A) Lambert’s law
(B) Stark-Einstein law
(C) Beer’s law
(D) Stark law
18. What happens to the intensity of a beam of monochromatic light as the concentration of the absorbing substance increases?
(A) Increases linearly
(B) Increases exponentially
(C) Decreases linearly
(D) Decreases exponentially