3.1 Reaction Rates and Rate Laws

Question 1

Reaction Rates

The speed at which a reaction takes place is govered by several factors

Answer 1

1. What the reactants are, and their concentrations: reactions tend to proceed faster at higher concentration concenrations
2. The temperature: ractions tend to proceed faster at higher temperatures
3. Whether or not a catalyst is present

Question 2

Reaction Rates

Relationship between the rates for various ractants and products are:

Answer 2

For any reaction:

aA + bB → cC + dD

the relationship is:

Rate=−1/a (∆[A]/∆t)=−1/b (∆[B]/∆t)=1/c (∆[C]/∆t)=1/d (∆[D]/∆t)

Question 3

Reaction Rates

Concentration Effects and Rate Laws

Answer 3

aA + bB → products

Rate Law: Rate=k[A]^x [B]^y

Where:

• k is the specific rate constant
• [A] and [B] are concentratons o components A and B in M
• x and y are the orders for each reactant and can only be found experimentally

Note: the expoents DO NOT correlate with the coefficients in the reaction equation

Question 4

Reaction Rates

Experimental determination of the exponents

Example 3.1.1:

For the following reaction, use the experimental data provided to determine the exponents and specific rate constant, k.

Answer 4

Question 5

Zero-Order Reactions

Summary of rate laws, integrated rate laws, half-lives, and units of k

Answer 5

Question 6

First-Order Reactions

Summary of rate laws, integrated rate laws, half-lives, and units of k

Answer 6

Question 7

Second-Order Reactions

Summary of rate laws, integrated rate laws, half-lives, and units of k

Answer 7