A first order reaction has a rate constant 1.15×10^−3s^−1. How long will 5g of this reactant take to reduce to 3g ? A first order reaction has a rate constant 1.15×10^−3s^−1. How long will 5g of this reactant take to reduce to 3g ? June 4, 2021 Category: Chemistry , NCERT Exemplar Class 12 ,