A second order reaction has a rate constant of 0.169 L/(mol-s). If the initial concentration of the reactant is 0.159 M, how long would it take for it to decrease to 6.07 x 10-3 M

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]