When phenacyl bromide and pyridine are both dissolved in...

When phenacyl bromide and pyridine are both dissolved in methanol, they react to form phenacylpyridinium bromide. When equal concentrations of reactants were mixed in methanol at $35^{\circ} \mathrm{C}$, these data were obtained: (a) What is the rate law for this reaction? (b) What is the overall order? (c) What is the rate constant? (d) What is the rate of this reaction when the concentration of each reactant is $0.030 \mathrm{~mol} / \mathrm{L}$ ?

When phenacyl bromide and pyridine are both dissolved in methanol, they react to form phenacylpyridinium bromide.
When equal concentrations of reactants were mixed in methanol at $35^{\circ} \mathrm{C}$, these data were obtained:
(a) What is the rate law for this reaction?
(b) What is the overall order?
(c) What is the rate constant?
(d) What is the rate of this reaction when the concentration of each reactant is $0.030 \mathrm{~mol} / \mathrm{L}$ ?

Key Concepts

Rate Law

The rate law is an equation that shows how the rate of a chemical reaction depends on the concentration of its reactants. It is typically written as rate = k[A]^m[B]^n, where k is the rate constant and m and n are the orders with respect to reactants A and B, respectively. This law is determined experimentally and reflects the mechanism of the reaction.

Reaction Order

Reaction order refers to the sum of the exponents of the concentration terms in the rate law. It indicates how the rate of reaction responds to changes in the concentrations of the reactants. The overall reaction order provides insight into the complexity of the reaction mechanism and the dependency of the reaction rate on the reactants.

Rate Constant

The rate constant is a proportionality factor in the rate law that connects the measured reaction rate to the concentrations of the reactants. It is specific to a given reaction at a particular temperature, and its units vary depending on the overall order of the reaction. The magnitude of the rate constant gives information about the speed of the reaction.

Reaction Rate Calculation

Calculating the reaction rate involves substituting the numerical values of the reactants' concentrations into the rate law equation. This process allows one to determine how fast the reaction proceeds under specific conditions, and it is a crucial step in comparing experimental data to theoretical predictions.

Transcript

00:01 To determine the order of the reaction and the rate law and everything else that we need to solve for this question, we need to plot the data provided.

00:10 We'll take the time in minutes and the corresponding concentration, and we'll plot concentration as a function of time.

00:19 If we get a straight line as represented by an r -squared value of at least 0 .99, with the plot of concentration as a function of time, it would be zero order.

00:30 Overall, if we get a straight line with the natural log of the concentration as a function of time, then it would be first order, which we don't.

00:43 If we get a straight line, .998, which we do here, when plotting one over the concentration as a function of time, then it's second order, and the slope is equal to the rate constant.

00:56 So what i had to do is i had to take the concentration, take the natural log of the concentration, and then calculate one over the concentration so that i could prepare all three of these graphs.

01:10 So what is the rate law? well, the rate law is going to be rate is equal to k multiplied by the reactant concentration squared, or it could be k multiplied by phenyl acetate raised to the one, no, we're not doing enelacitate.

01:46 We're doing phenyloid bromide.

01:51 It'll be phenyloid raised to the one.

01:59 And then pirating raised to the one.

02:04 The overall order is second, but each one is going to be individually first order...

Please give Ace some feedback