Question

In the first-order reaction a→products, the concentration of the reactant decreases to 6.25% of its initial value in 80min.What is rate constant

Answer 1

Explanation with calculation in the attachment. Hope it helps :)

Answer 2

The specific rate constant (k) is the proportionality constant relating the rate of the reaction to the concentrations of reactants. The rate law and the specific rate constant for any chemical reaction must be determined experimentally. The value of the rate constant is temperature dependent.