Answer
See the answer below.
Work Step by Step
a) From the table, doubling the concentration of NO, at the same H2 concentration, leads to the reaction rate being quadrupled, so the reaction is of order 2 in NO. Doubling the concentration of H2, at the same NO concentration, leads to the reaction rate being doubled, so the reaction is of order 1 in H2.
b) $r=k[NO]^2[H_2]$
c) From the first line of the table:
$0.136\ mol/L.s=k(0.420\ mol/L)^2(0.122\ mol/L)$
$k=6.32\ L^2/mol^2.s$
d) $r=6.32\times(0.350)^2(0.205)=0.157\ mol/L.s$, from stoichiometry this is the rate of formation of N2.