NH4+(aq) + NO2−(aq) → N2(g) + 2H2O(l) is given by rate = k[NH4+][NO2−]. At a certain temperature, the rate constant is 4.10 × 10−4 /M·s. Calculate the rate of the reaction at that temperature if [NH4+] = 0.301 M and [NO2−] = 0.160 M.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.