:at a certain temperature this reaction follows first-order kinetics with a rate constant of 0.00771 nh, oh(aq) - nh, (aq) +h,0(aq) suppose a vessel contains nh oh at a concentration of 1.42 m. calculate how long it takes for the concentration of nh oh to decrease to 17.0% of its initial value. you may assume no other reaction is important round your answer to 2 significant digits. x 5 ?