Question

What is the first – order decay?

(a) The rate of loss of the pollutant is constant

(b) The rate of loss of the reactant is constant

(c) The rate of loss of the pollutant is directly proportional to its concentration

(d) The rate of loss of the reactant is directly proportional to its concentration

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Answer 1

The correct choice is (c) The rate of loss of the pollutant is directly proportional to its concentration

For explanation: First – order decay is the rate of loss of the pollutant is directly proportional to its concentration:

|dc/dt|reaction = -kC

For such a pollutant, mreaction = – V kC.