Absorbance and Transmittance Calculation Quiz

Quantum Yield and Photons

• Quantum yield is the number of molecules reacted per photon absorbed, calculated as the number of molecules reacted divided by the number of photons absorbed.
• If 0.01 moles of HI molecules decompose to produce 3.0115×10^22 photons, the quantum yield for the decomposition can be calculated.

Electronic Transitions and UV Spectra

• The peak at λmax=280 nm in the UV spectrum of acetone corresponds to a specific electronic transition.
• The peak at λmax=190 nm in the UV spectrum of acetone corresponds to a different electronic transition.

IR Spectra and Carbonyl Group

• The stretching vibration of the carbonyl group in simple aldehydes and ketones typically exhibits IR absorption in a specific range.

Molecular Vibration and Force Constant

• The fundamental frequency of vibration of a CO molecule can be calculated using its force constant, which is 2.66 x 10^3 N/m.

Absorbance and Transmittance

• The absorbance of a dye solution can be calculated from its transmittance, which is 30% at 600 nm.
• The absorbance of a 0.02 M dye solution in a 3 cm cell can be calculated for light of wavelength 6000Ao with a percentage transmittance of 40%.

Quantum Yield and Reaction Efficiency

• A quantum yield of 0.8 indicates that 80% of the absorbed photons result in a reaction.

Stereochemistry

• Stereochemistry is the study of molecules as three-dimensional objects, not two-dimensional objects.

Quantum Yield and Reaction Rate

• If a substance absorbs 3.5 x 10^18 photons of light per second and 0.003 mole of it reacts in 25 minutes, the quantum yield of the reaction can be calculated.

Beer-Lambert Law

• The Beer-Lambert Law governs the relationship between the absorbance, molar absorption coefficient, concentration, and thickness of a solution.

Types of Isomerism

• Structural isomerism refers to isomers with the same molecular formula but different arrangement of atoms.
• Chain isomerism arises due to the difference in arrangement of carbon atoms within a molecule.
• Optical isomerism is a type of structural isomerism where the atoms are arranged in a non-superimposable manner.
• Tautomerism refers to compounds having the same molecular formula but different structural and physical/chemical properties.
• Functional group isomerism involves isomers with the same functional groups.
• Position isomerism involves the movement of important groups around the basic carbon skeleton.
• Ring-chain isomerism involves compounds with different molecular formulas.
• Metamerism is a type of isomerism where the atoms are arranged in a different order.