The rate law (rate equation) shows the mathematical relationship between rate and concentration of substances upon which rate depends. Ultimately, it gives chemists clues about the detailed pathway (mechanism) for the reaction.
Order indicates how many A and B participate in the rate-determining (slowest) step.
The reaction having the rate law (rate equation) above is
If x is 1, then it is first order in A.
If y also is 1, it is first order in B.
The overall reaction order is the sum of the exponents on its experimentally-determined rate law.
For a reaction:
aA+bB
cC+dD
the differential rate equation may have the form:
The exponents x and y must be experimentally determined.
The exponent is the power to which the concentration is raised to calculate rate.
Exponents 1 and 2 are common (for exponent 2 concentration is squared).
If the rate of reaction does not depend on the concentration of a reactant, the exponent on that concentration is 0 because [B]0 equals 1.
The rate constant k depends on the reaction and the temperature at which it is carried out.
aA+bB
cC+dDthe differential rate equation may have the form:
rate = k[A]x[B]y
The exponents x and y must be experimentally determined.
The exponent is the power to which the concentration is raised to calculate rate.
Exponents 1 and 2 are common (for exponent 2 concentration is squared).
If the rate of reaction does not depend on the concentration of a reactant, the exponent on that concentration is 0 because [B]0 equals 1.
The rate constant k depends on the reaction and the temperature at which it is carried out.
The order of the reaction in a substance is given by the exponent on its concentration in the rate law (rate equation).
Order indicates how many A and B participate in the rate-determining (slowest) step.
The reaction having the rate law (rate equation) above is
x order in A
y order in B
y order in B
If x is 1, then it is first order in A.
If y also is 1, it is first order in B.
The overall reaction order is the sum of the exponents on its experimentally-determined rate law.
The overall reaction order for the reaction with the rate law given above would be x + y.
If both x and y are 1 (as above), the overall reaction order is 2.
The reaction is said to be second order.
If both x and y are 1 (as above), the overall reaction order is 2.
The reaction is said to be second order.