Do Now - Steady State Approximation & Multistep Reaction Profile

Consider the following mechanism:

A₂ + B₂ ↔ R + C (fast)

A₂ + R → C (slow)

Which is the intermediate?

• A₂

• A

• B

• R

• C

Consider the following mechanism:

A₂ + B₂ ↔ R + C (fast)

A₂ + R → C (slow)

What is the overall simplified balanced equation?

• A₂ + B₂ → R + C

• A₂ + R → C

• 2A₂ + B₂ → 2C

• 2A₂ + B₂ → C

• 2A₂ + 2B₂ → 2C

Consider the following mechanism:

A₂ + B₂ ↔ R + C (fast)

A₂ + R → C (slow)

What is the rate law?

• =k[A]²[B]²

• =k[A₂][B₂]

• =k[A₂]²[B₂][C]

What is the catalyst in the following rate mechanism?

• HBr

• H₂O

• There is no catalyst

How many different intermediates are in the following rate mechanism?

• 0

• 1

• 2

• 3

What is the rate law for the following reaction?

• =k[HBr][O₂]²

• =k[HBr]²[O₂]

• =k[HBr][O₂]

• =k[HBr]²[O₂]/[HOOBr]

What is the rate law expression for the following mechanism?

Step 1 AB + C₂ ,<-> AC₂ + B fast

Step 2 B + AB →  AB₂ slow

Step 3 AC₂ + AB₂ →  A₂C₂ + B₂ fast

Step 4A₂Cv + B₂  → A2C + B₂C fast

What letter represents the activation energy?

• A

• B

• C

• D

Given the reaction mechanism below:

1. B₂ + 2A --> A₂B + B⁺ (slow)

2. A₂B + C --> A₂ + CB (fast)

Which of the following rate laws agree with the proposed reaction mechanism?

• Rate=k[B]²[A₂]

• Rate=k[A]²[B₂]

• Rate=k[B₂][A]²[C]

• Rate=k[A₂B][C]

Consider the reaction mechanism given below:

1. NO + O₃ --> NO₂ + O₂

2. O₃ --> O₂ + O

3. NO₂ + O --> NO + O₂

Which of the following correctly identifies the role of NO and explains why?

• NO is a catalyst. In a reaction mechanism, catalyst first appear as a product and leave as a reactant.

• NO is a intermediate. Intermediates are formed as a result of a fast initial step.

• NO is a intermediate. Intermediates appear as a reactant and is released as a product in a later step.

• NO is a catalyst. The presence of NO increases the rate of the reaction.