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With 1st order kinetics in each reaction:

A -----> B k1 = 0.110 s-1

A ----->C k2 = 0.025 s-1

B ----->C k3 = 75.2 s-1 (plot twist)

C-----> D k4 = 17.2 s-1

If starting concentration A = 0.016 M

1. How much reactant A is after 25 s? 2. Use the Steady State approximation to derive the velocity expression for the occurrence of D and thus calculate [D] after 25s? 3. If the experiment is repeated but with added inhibitor so that k3 = 0 (but the other reactions are unaffected) calculate [D] when the reaction is over?