I have a very difficult problem and I need help. Under certain conditions the rate of this reaction is zero order in dinitrogen monoxide with a rate constant of 0.0055·Ms−1: 2N2O(g)→2N2(g)+O2(g) Sup

pose a 3.0L ⁢ flask is charged under these conditions with 400.mmol of dinitrogen monoxide. After how much time is there only 200.mmol left? You may assume no other reaction is important.

Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.