How to solve.  This method requires that a reaction be run several times.  The initial concentrations of the reactants are varied.  The reaction rate.

Slides:



Advertisements
Similar presentations
Rate Laws. Rate = k [A] x [B] y [A] and [B] represent the concentrations of reactants x and y often (but not always) represent the coefficients in front.
Advertisements

Chem Ch 28/#1 Todays To Do List Chemical Kinetics: Rate Law – What is it? - Experimental methods.
Rate Law Learning Goals:
R a t e s O f C h e m i c a l R e a c t i o n s. R e a c t i o n R a t e F o r a r e a c t i o n t o o c c u r, p a r t i c l e s m u s t c o m e t o.
Kinetics Made Simple 2N 2 O 5 (aq)  4NO 2 (aq) + O 2 (g) Example 1:
Learning Goals Students will: understand the Rate Law Equation determine the Rate Law Equation given experimental data.
Review Problems. Water can be made from hydrogen and oxygen: H 2 (g) + O 2 (g) → H 2 O (g) Some experiments are run in a sealed 1 L flask at 350 K to.
Chemical Kinetics A Study of the Rates of Reactions.
Chapter 13: Chemical Kinetics CHE 124: General Chemistry II Dr. Jerome Williams, Ph.D. Saint Leo University.
Rate Law 5-2 an expression which relates the rate to the concentrations and a specific rate constant.
Chemical Kinetics CHAPTER 14
11.2 Reaction Rate and Concentration
Rate Laws Chapter 14 part II Rate Laws Chemical reactions are reversible. So far we have only considered the forward reaction in our rates. Eventually.
Kinetics  The study of reaction rates.  Spontaneous reactions are reactions that will happen - but we can’t tell how fast.  Graphite will spontaneously.
Chemical Kinetics H 2 O 2 decomposition in an insect H 2 O 2 decomposition catalyzed by MnO 2 Day 2: Rate equations.
CHAPTER 12 Chemical Kinetics.
Sometimes using simple inspection of trials cannot be used to determine reaction rates Run #[A] 0 [B] 0 [C] 0 v0v M0.213 M0.398 M0.480 M/s
Kinetics l The study of reaction rates. l Spontaneous reactions are reactions that will happen - but we can’t tell how fast. l Diamond will spontaneously.
Kinetics l The study of reaction rates. l Spontaneous reactions are reactions that will happen - but we cannot tell how fast. l Diamond will spontaneously.
KINETICS The speed of a reaction. Kinetics The study of reaction rates. Spontaneous reactions are reactions that will happen - but we can’t tell how fast.
 The study of reaction rates and steps.  Spontaneous reactions are reactions that will happen - but we can’t tell how fast.  Diamond will spontaneously.
Dr. Harris Lecture 18 HW: Ch 17: 5, 11, 18, 23, 41, 50 Ch 17: Kinetics Pt 1.
Integrated Rate Laws How to solve.
Chemical Reactions. Which of the following indicated that the reaction was completed in the experiments? A. Solution A was added to Solution B. B. The.
Measuring Reaction Rates Continuous monitoring polarimetry spectrophotometry total pressure Taking aliquots gas chromatography titration for one of the.
Title: Lesson 4 Determining Reaction Order and Rate Equation Learning Objectives: – Build on our understanding of reaction order to construct rate equations.
17.2 The equilibrium law Solve homogeneous equilibrium problems using the expression for Kc. –The use of quadratic equations will NOT be assessed.
Second and Zero rate orders Chapter 14 part IV. Second Order Rate Laws  Butadiene forms its dimer  2C 4 H 6 (g) - > C 8 H 12 (g)
TOPIC C: REACTION MECHANISMS. Mechanism - the sequence of elementary steps that make up a chemical reaction Each step will be relatively fast or relatively.
Kinetics Lab A little help to get you started. PreLab Q1 Hint: The reaction time is NOT the rate. Time = sec Rate = mol/L sec To find the rate of each.
6-3:Calculating Equilibrium Constants: The actual value of K eq is found experimentally. The individual concentrations of all the reactants is calculated,
Rate Laws.  Determine the rate law from experimental data.  Explain the effect of concentration on reaction rates.  Derive rate law form a reaction.
Determining Order of Rate Law. Rate = k [A] n The order of the reactants in the rate law can only be determined experimentally The initial rate is determined.
Kinetics- Partial Notes. BrO Br - +6H +→ 3Br 2 + 3H 2 O Find the rate law and calculate k Experime nt [BrO 3 - ] [Br - ][H + ]Initial Rate Mol/L.
Reaction Rates Measures concentration (molarity!) change over time Measures concentration (molarity!) change over time Example: Example: 2H 2 O 2  2H.
Reaction Rates: 2 NO2  2 NO + O2 change in conc. 1. slope =
Kinetics. Definition Kinetics is the study of reaction rates Reaction Rate is the speed of reaction Reaction rate is measured as the change in concentration.
*Measuring how fast reactions occur. Lecture 2: Stoichiometry & Rate Laws.
6.5 Rate Laws & Order of Reaction Rate Law The rate (r), is proportional to the product of the initial reactant concentrations raised to some exponent.
16.1 Rate Expression. Assessment Statements Distinguish between the terms rate constant, overall order of reaction and order of reaction with respect.
AP Notes Chapter 15 Principles of Reactivity: Chemical Kinetics.
DIFFERENTIAL RATE LAW A few things first… Reactions are reversible and the reverse reaction is important. When the rate of the forward reaction equals.
Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs.  The sum of the elementary steps must.
Quantitative Changes in Equilibrium Systems Chapter 7.5.
Q is the reaction quotient Gives the condition of the reaction at any point during the reaction. [X] o indicates the initial concentration of a species.
CHAPTER 12 AP CHEMISTRY.
SECTION 1. THE REACTION PROCESS
Kinetics The study of reaction rates.
Explaining Reaction Rates
Determining the Form of the Rate Law
RATE LAWS!!! Reaction rate video:
OBJECTIVES: RATE LAW, ORDER OF REACTION, k
Rate Laws Chemical reactions are reversible. 2NO2(g) → 2NO(g) + O2(g)
Kinetics Part II: Rate Laws & Order of Reaction
Equilibrium Expressions mass-action expression
AP Chemistry B Exam Prep Session Kinetics
Kinetics Part II: Rate Laws & Order of Reaction
Rate Orders.
Integrated Rate Law: First-Order
OBJECTIVES: RATE LAW, ORDER OF REACTION, k
For Reaction Rates and Mechanisms
Reaction Rate Change in concentration of a reactant or product per unit time. [A] means concentration of A in mol/L; A is the reactant or product being.
Kinetics Lesson # 3 Rate Law.
Determining the Form of the Rate Law
Unit 4: Solutions and Kinetics
Integrated Rate Law By Chloe Dixon
Studio 9a 10/30/06.
Ch11. Integrated rate laws and reaction mechanisms
Termolecular.
Presentation transcript:

How to solve

 This method requires that a reaction be run several times.  The initial concentrations of the reactants are varied.  The reaction rate is measured just after the reactants are mixed.  Eliminates the effect of the reverse reaction.

A + 2B 3C + D [A] [B] Initial Rate ?

Rate = k[A] x [B] y Take any two experiments where the [ ] of one species is held constant = k[.240] x [.480] y 2.00 = k[.240] x [.120] y 4.00 = 4 y therefore, y = 1

Now repeat the process, holding the other [ ] constant = k[.240] x [.120] y.500 = k[.120] x [.120] y 4.00 = 2 x therefore, x = 2

Rate = k[A] 2 [B] Determine the value of k with units: 8.00 = k[.240] 2 [.480] 290 L 2 /mol 2 sec = k Determine the initial rate for the last experiment rate = 290[.0140] 2 [1.35] rate =.0767 mol/l sec

 For the reaction BrO Br - + 6H + 3Br H 2 O  The general form of the Rate Law is Rate = k[BrO 3 - ] n [Br - ] m [H + ] p  We use experimental data to determine the values of n, m, and p

Initial concentrations (M) Rate (M/s) BrO 3 - Br - H+H+H+H x x x x x x x x Now we have to see how the rate changes with concentration

x = 1 y = 1 z = 2 Rate Law = k[BrO 3 - ][Br - ][H + ] 2