Telegram group: T.me/BBCNOUN [CHM414] Identify the correct statement. The free energy change of a thermochemical reaction is always negative [CHM414] Why are medicine bottles are often made with darkened glass? to prevent photodegradation [CHM414] The overall quantum yield for a reaction at 290 nm is 0.30. For what length of time must irradiation with a 100 W source continue in order to destroy 1.0 mol of molecules? 3.8 hrs [CHM414] The quantum efficiency of a photochemical reaction is defined as _______ ratio of molecules decomposed in a given time to the number of quanta absorbed in the same time [CHM414] Which is the second law of photochemistry? Stark-Einstein law [CHM414] Which of the following will result in deviation from Beer’s law? (A) Change in a refractive index of medium (B) Dissociation of analyte on dilution (C) Polychromatic light (D) Path length of cuvette A, B and C [CHM414] A substance absorbs 2.0 x 1016 quanta or radiations per second and 0.002 mole of it reacts in 1200 seconds. What is the quantum yield or the reaction (N = 6.02 x 1023)? 50 [CHM414] The number of events which occur per photon absorbed by a system is quantum yield [CHM414] Which of the following are the reactions in which molecules absorbing light do not themselves react but induce other molecules to react? Photosensitized reactions