The reaction rate law is known to be 2nd order, and for an initial concentration [NO2(g)]o=0.0100M, the initial rate is 0.0350 M/s. Write the rate law, and give the value of the rate constant?

Consider the following reaction:

2 NO2(g) -> 2 NO(g) + O2(g)

The reaction rate law is known to be 2nd order, and for an initial
concentration [NO2(g)]o=0.0100M, the initial rate is 0.0350 M/s. Write
the rate law, and give the value of the rate constant.

1 Answer
Dec 12, 2016

The rate law is #"rate" = k["NO"_2]^2#; #k ="350 L·mol"^"-1""s"^"-1"#.

Explanation:

#"2NO"_2 → "2NO" + "O"_2#

If the reaction is second order and #"NO"_2# is the only reactant, the rate law is

#"rate" = k["NO"_2]^2#

#k = "rate"/(["NO"_2]^2) = ("0.0350 mol·L"^"-1""s"^"-1")/("0.0100 mol·L"^"-1")^2 = "350 L·mol"^"-1""s"^"-1"#