A chemistry graduate student is studying the rate of this reaction: 2SO3 (g) ---> 2SO2(g)+O2(g) He fills a reaction vessel with and measures its concentration as the reaction proceeds: time [SO3] (milliseconds) 0 0.900M 10. 0.600M 20. 0.400M 30. 0.267M 40. 0.178M Use this data to answer the following questions.

Write the rate law for this reaction.

rate =k

Calculate the value of the rate constant k .

Round your answer to 2 significant digits. Also be sure your answer has the correct unit symbol.

k=