A Certain First-Order Reaction a → B Is 25% Complete

question 70

Multiple Choice

A certain first-order reaction A → B is 25% complete in 42 min at 25°C. What is its rate constant?

• A) 6.8 × 10^-3 min^-1
• B) 8.3 × 10^-3 min^-1
• C) 3.3 × 10^-2 min^-1
• D) -3.3 × 10^-2 min^-1
• E) 11 min^-1

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Definitions:

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A hormone produced by the stomach that stimulates appetite, increasing food intake and promoting fat storage.

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A medical condition characterized by an excess of body fat to the extent that it may have a negative effect on health.

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A chemical substance produced in the body that regulates hunger, such as ghrelin.