# Chemistry

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The reaction between NO (nitric oxide) and oxygen is a key step in the formation of
acid rain.

O2(g) + 2NO(g) → 2NO2(g)

A series of experiments were run, each of which starts with a different set of reactant concentrations. From each experiment an initial rate of reaction was obtained.

======Initial concentration=========
==== mol dm-3 ========= == ====Initial rate of reaction=========
======================= = ===(mol dm-3 s-1)
Expt.------- [O2] ======------ [NO]
1) ---- -- 1.10x10-2 === 1.30x10-2 == 3.20 x 10-3
2 --- -- 2.20x10-2 === 1.30x10-2 == 6.40 x 10-3
3 --- -- 1.10x10-2 === 2.60x10-2 == 1.28 x 10-2
4 ----- 3.30x10-2 === 1.30x10-2 == 9.60 x 10-3
5 ----- 1.10x10-2 === 3.90x10-2 == 2.88 x 10-2

a) Using the data from the table, determine the orders of reaction with respect to O2 and NO. Explain your reasoning.

(b) Write a rate equation for this reaction.

(c) Determine the overall order of reaction.

(d) Calculate the rate constant (k) for this reaction, express your answer to the appropriate number of significant and give the units

• Chemistry - ,

#1 and #5 will give you the order for NO which I see as 2.

#1 and #2 will give you the order for O2 which I see as 1 so the rate constant expression is
rate = k[NO][O2]2

The overall order is the sum of the individual orders.

Take any one experiment and substitute the number into the rate expression; solve for k.

• Chemistry - ,

thank you. I don't understand why the O2 is to the power of two in the rate = k[NO][O2]2 when that is only a first order reaction and the NO is second order.