Cаlculаte the rаte оf change оf the phenyl acetate cоncentration (in mol/L*s) during the period 15.0 seconds to 20.0 seconds: Time (s) [Phenyl acetate] (mol/L) 0 [x] 15.0 [y] 20.0 [z] 45.0 0.20 60.0 0.17 75.0 0.12 90.0 0.085 (Report your answer to four decimal places, i.e. x.xxxx) (Remember to include a negative sign, if necessary.)