How Does Changing Concentration Affect the Rate of a Chemical Reaction?

AI Thread Summary
The discussion centers on the reaction 2NO(g) + O2(g) ---> 2NO2(g), which is second order in NO and first order in O2. The observed rate of disappearance of NO is given as 0.00017670 M/s with initial concentrations of 1 M for NO and 1.9 M for O2. The rate constant has been determined to be 2 M-2s-1, and increasing the concentration of NO by 1.4 times is expected to increase the reaction rate. The user seeks help in calculating the new rate of reaction and understanding the implications of the reaction's order. Clarification on the meaning of "second order in NO" and guidance on applying the rate equation are requested.
tensirk
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Homework Statement


The reaction 2NO(g) + O2(g) ---> 2NO2(g) is second order in NO and first order in O2.
When [NO] = 1 M and [O2] = 1.9 M, the observed rate of disappearance of NO is 0.00017670 M/s.

I have already found the value of the rate constant to be 2. I found that the units of the rate constant are M-2s-1. I lastly found that the rate of the reaction would increase if the concentration of NO were increased by a factor of 1.4.

Now I am having a lot of trouble figuring out these last two problems:
1. By what factor would the rate of reaction of NO increase? [if it were increased by a factor of 1.4]
2. What is the rate of reaction when [NO] = 0.1 M and [O2] = 0.19 M?

Homework Equations


Honestly, I don't even know where to begin in terms of equations for these two problems.

The Attempt at a Solution


I think where I'm having trouble is understanding what "second order in NO" means. Any guidance on these problems would be MUCH appreciated, as I feel completely lost. Thanks in advance!
 
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v=k[O2][NO]2
 
The "orders" are the powers to which the concentrations are raised. These come from the stoichiometric ratios of the reactants.
 
cep said:
The "orders" are the powers to which the concentrations are raised. These come from the stoichiometric ratios of the reactants.

Not necessarily. For instance, the rate of halogenation of acetone is proportional to the concentration of acid, and is independent of the concentration of halogen.
 
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