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At 27 deg C consider two reactions: (I) A -> B, first-order kinetics (II) X -> Y, zero-order kinetics Both A and X start at the same initial concentration of 0.1 M and have the same half-life. Find the simplest ratio of the rate constants k(I): k(II). [ln 2 = 0.7]
- 1: 7
- 7: 1
- 1: 14
- 14: 1
Correct answer: 14: 1
Solution
Equating half-lives: ln2/k1 = [A0]/(2 k0). So k1/k0 = 2 ln2/[A0] = (2 x 0.7)/0.1 = 14, giving k(I):k(II) = 14:1.
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