Consider the 2-step reaction mechanism
fast 2NO + H2 $ N2O+H2O
slow N2O+H2 ! N2+H2O
net 2NO + 2H2 ! N2 + 2H2O
Which of the following rate laws is cor-
rect for the given mechanism? Note that the
constant k may represent a combination of
elementary reaction rate constants.
Which of the following rate laws is cor-
rect for the given mechanism?
You have not shown any rate laws.
the rate law choices are:
1. rate in respect to net=k[NO][H2]
2. rate net=k[NO]^2[H2]^2
3. rate net=k([H2]^2[NO]^2)/[H2O]
4. rate net=k[NO]^2[H2]
5.rate net=k([N2][H2O]^2[H2]^2)/[NO]^2
please help! :)
To determine the rate law for the given reaction mechanism, we need to examine the slow step of the mechanism, as it is the rate-determining step.
From the given mechanism, the slow step is:
N2O + H2 -> N2 + H2O
The stoichiometric coefficients in the balanced equation for the slow step give us the following rate law:
Rate = k[N2O][H2]
Therefore, the correct rate law for the given mechanism is:
Rate = k[N2O][H2]
To determine the correct rate law for a given reaction mechanism, we need to consider the slowest step in the mechanism. This is known as the rate-determining step. The rate law is based on the reactants and their reaction orders in the rate-determining step.
In this case, the slow step is the second step: N2O + H2 → N2 + H2O. Let's analyze this step:
From the equation, we see that the reactants are N2O and H2. The products are N2 and H2O. The coefficient in front of N2O is 1, and the coefficient in front of H2 is also 1.
Since the rate-determining step involves the concentration of N2O and H2 as reactants, we can write the rate law as:
Rate = k[N2O]^a[H2]^b
The exponents "a" and "b" represent the reaction orders for N2O and H2, respectively. To determine these exponents, we need experimental data.
Therefore, without additional information or experimental data, we cannot determine the specific rate law for the given mechanism.