The rate constant for a reaction is 4.65 L mol-1s-1. The overall order of the reaction is:
zero
first
second
third
I am having trouble with the order of reactions. I don't understand this question. this is an assignment question but i have no idea how to do it.
The units tell you the order.
Look under this link for second order. (And write down the others). This is good to remember.
http://chemistry.about.com/od/lecturenotesl3/a/reactionorder.htm
thanks again DR BOB! this whole chemistry thing is a kick in the pants when you just cant get your head around it!
To determine the overall order of a reaction, you need to consider the individual orders of the reactants involved in the rate equation. The rate equation represents the relationship between the concentration of the reactants and the rate of the reaction.
In this case, the rate constant for the reaction is given as 4.65 L mol^-1s^-1. The units of the rate constant can give you a clue about the orders of the reactants.
For a zero-order reaction, the rate is independent of the concentration of the reactants. In other words, changing the concentration of the reactants does not affect the rate of the reaction. The rate constant for a zero-order reaction would have units of mol L^-1s^-1.
For a first-order reaction, the rate is directly proportional to the concentration of only one reactant. If the rate constant has units of s^-1, it indicates a first-order reaction.
For a second-order reaction, the rate is directly proportional to the concentration of two reactants or the square of the concentration of one reactant. The rate constant for a second-order reaction has units of L mol^-1s^-1.
For a third-order reaction, the rate is directly proportional to the concentration of three reactants or the product of the concentrations of two reactants and the square of the concentration of one reactant. The rate constant for a third-order reaction has units of L^2 mol^-2s^-1.
Since the rate constant in this case has units of L mol^-1s^-1, it indicates a second-order reaction. Thus, the overall order of the reaction is second.
Determining the overall order of a reaction can be a little confusing at first, but let me guide you through the process step by step.
To determine the overall order of a reaction, we need to consider the individual orders of each reactant and combine them. The order of a reactant tells us how the rate of the reaction changes with respect to changes in concentration of that specific reactant.
In your case, we are given the rate constant for the reaction, which is 4.65 L mol-1s-1. This rate constant alone does not provide any information about the orders of the reactants. We need additional information for that.
To determine the overall order, we can use the method of initial rates. This involves comparing the initial rates of the reaction under different conditions with varying reactant concentrations. By comparing the rate ratios, we can find the order.
Let's consider a generic reaction:
A + B → products
To determine the order of the reactants A and B, we set up a series of experiments where we vary the concentrations of A and B, while keeping the other reactant constant.
Suppose we have three experiments with the following reactant concentrations:
Experiment 1: [A]₀, [B]₀
Experiment 2: 2[A]₀, [B]₀
Experiment 3: [A]₀, 3[B]₀
Now, we observe the initial rates of reaction for each experiment:
Rate₁ = k[A]₀^a[B]₀^b
Rate₂ = k[2A]₀^a[B]₀^b
Rate₃ = k[A]₀^a[3B]₀^b
By comparing the ratios, we can determine the orders of A and B:
Rate₁/Rate₂ = (k[A]₀^a[B]₀^b) / (k[2A]₀^a[B]₀^b)
Rate₁/Rate₂ = (1/2)^a
Rate₁/Rate₃ = (k[A]₀^a[B]₀^b) / (k[A]₀^a[3B]₀^b)
Rate₁/Rate₃ = (1/3)^b
By comparing these rate ratios, we can find the values of a and b, which correspond to the orders of A and B, respectively.
In your case, if you were not provided with any additional information, it would be difficult to determine the overall order of the reaction. The rate constant alone is not sufficient for that. You may need additional details or experimental data to calculate the order.
However, if you were given the orders of the reactants, you could simply sum them up to find the overall order of the reaction. For example, if the order of reactant A is 1 and the order of reactant B is 2, the overall order would be 1 + 2 = 3.
I hope this explanation helps you understand how to determine the overall order of a reaction. If you have any further questions, feel free to ask!