Q3. Kinetics. Answer all parts. (a) For 900 s, light of 426 nm was passed through a solution of Br2 and cinnamic acid in
Posted: Thu Dec 02, 2021 5:13 am
Q3. Kinetics. Answer all parts. (a) For 900 s, light of 426 nm was passed through a solution of Br2 and cinnamic acid in tetrachloromethane. The average power absorbed was 1.92 x 10-'Js! Some of the Br2 reacted to form cinnamic acid di-bromide and in this experiment the total di-bromine content decreased by 3.83 x 10" molecules. (1) Calculate the quantum yield of the reaction. [60 marks) (ii) Comment on the result. [10 marks] (b) By referring to Figure 1, or otherwise, discuss the concept of observing the transition region of a reaction via femtosecond transition-state spectroscopy. [30 marks) V (R) V,(R) I + CN(B2L") 390.4 nm hy 388.5 nm Relative Potential Energy -1.CN(XSE VO(R) =1.CN(XXL) 306 nm PUMP 2. 1 2.5 0.0 3.0 I. CN Distance (8)