Under identical concentrations and temperature, the rate constant for a particular reaction is k1=1.6×10−4s−1 in the absence of a certain solid additive and k2=4.0×10−2s−1 when the additive is present. Approximately how many times faster is the initial rate when the additive is used?
a) 2.5×104
b) 2.5×102
c) 2.5×105
d) 2.5×103