Identify the modes of catalysis and when / why they occur • Acid-base • Covalent • Transition state stabilization

what is the approximation used to derive the reaction rate for an enzyme catalysed reaction that proceeds by a michaelis menten mechansim

The acid-catalysed conversion of γ-hydroxybutyric acid (GHBA) into its lactone, γ-butyrolactone (GBL) is a reversible reaction. The GHBA to GBL forward reaction is first-order with respect to the GHBA concentration; the GBL to GHBA reverse reaction is first-order with respect to the GBL concentration. An experimental study of the kinetics of this reaction was undertaken in 0.2 mol L​​​​​​​-1hydrochloric acid (HCl) at 298 K. The initial concentration of GHBA was 18.23 × 10-3mol L-1 . The concentration of GBL in solution was followed as a function of time (t), as indicated in Table B.3: Time/min 0 21 36 50 65 80 100 ∞ GBL Concentration / 10-3 L-1 0 2.41 3.73 4.96 6.10 7.08 8.11 13.28 Use the data in Table B.3 to determine the equilibrium constant and the first-order rate constants for both forward and reverse reactions.

In the unimolecular gas phase reaction kinetics, what is the rate equation for the deactivation of the energized molecule A*? d[A*]/dt=-k'a[A] [A*] d[A*]/dt=ka[A]? O d[A*]/dt=-k½[A*] d[A*]/dt=k[A*]

The activation energy for the gas phase decomposition of cyclobutane is 262 kJ. (CH₂) 4- →2 C₂H4 The rate constant at 721 K is 0.000401 /s. The rate constant will be 0.00338/s at K.

What is the correct mechanism ?