Question

A first-order reaction has a specific reaction rate of 10⁻3 s⁻1. How much time will it take for 10 g of the reactant to reduce to 2.5 g? (Given log 2 = 0.3010, log 4 = 0.6021, log 6 = 0.778)
a) 691 seconds
b) 345 seconds
c) 172 seconds
d) 86 seconds