48. Which sequence of state-t0-state transitions for a diatomic system is requir

Question

48. Which sequence of state-t0-state transitions for a diatomic system is required for one to observe fluorescence with wavelength longer than that for the excitation photon? CB) Singlet Triplet Singlet Singlet Triplet Singlet EGA Singlet Singlet The mechanism of an enzyme catalyzed reaction of a substrate (S) to yield products (P) can be written 49· where ES and EP represent the enzyme-substrate and enzyme-product complexes, respectively. For this mechanism, the potential energy diagram (potential energy or enthalpy versus reaction coordinate) would be expected to have how many maxima? (A) one (B) two(C) three (D) four s0 For the concerted reaction A+B C+D E,(forward) is 46 kJ-mot and AH-27 J-mol-1 Therefore, E, (in units of kJ-mol-1) for the reverse reaction is (A) 19 (B) 27 (C) 46(D) 73

Explanation / Answer

48) D is correct as in fluorescence spin multiplicity remains same means singlet to singlet only transition occurs. A & D both involves singlet to singlet transition, but longer wavelength transition is in D as it involves emission of less energy .

49) Two maxima will be formed each represent the energy of intermediate ES and EP, they are higher in energy means less stable than reactants and products.

50) 73kJmol-1 as reaction is exothermic so reactants are at higher energy than products by 27 kJ , so to cross barrier product requires 46+27=73kJ of energy to convert back into reactants.

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.