Reaction rate
What is reaction rate?
Review: What is a chemical reaction? Chemical reactions are… when atoms react to produce a molecule/compound
F + F à F2 Reactants
Products
F
F
F2
What is reaction rate? Reaction rate is…
What is your heart rate?
the speed of a chemical reaction.
Fe + O2 à Fe2O3
CH4 + O2 à CO2 + H2O
Slow…
Fast!
Product Product or or reactant? reactant?
What is reaction rate? Reaction rate can be measured in two ways: 1. How fast the reactants disappear How fast the products appear reactant
12:00pm What if the rate was faster?
product
12:30pm
Example #1 What are two different ways to describe the below chemical reaction?
1. How fast the
disappear
amount
The decrease in the concentration of the reactants
How fast the
appear
The increase in the concentration of the products
Example #2 What are two different ways to describe the below chemical reaction?
CH4 + O2 à CO2 + H2O reactants
The decrease in the concentration of CH4 and O2 The increase in the concentration of CO2 and H2O products
Example #3 True or false (and if false, correct it).
H2O2 à O2 + H2 The rate of the above reaction can be measured as the increase in H2 and H2O2.
False
Exit Slip 1. What is the simple definition of reaction rate? a. the amount of kinetic energy in a substance b. the number of products in a reaction c. the amount of energy needed to change a substance from one phase to another d. the speed of a reaction
Exit Slip 2. What is the measurable definition of reaction rate?
a. b. c. d.
The increase in the concentration of the reactants The decrease in the concentration of the reactants The decrease in the concentration of the products None of the above
Exit Slip 3. If the rate of below reaction was faster, which would be a true statement.
a. the concentration of squares in the middle box
would be higher b. the concentration of squares in the middle box would be lower c. there would be no change to the reaction d. the concentration of circles in the middle box would be lower
Exit Slip 4. Which of the following describes the rate of the chemical reaction,
H2 + O2 à H2O an increase in the concentration of H2O and H2 with time an increase in the concentration of H2O with time
4. an increase in H2 and O2 with time a decrease in H2O and O2 with time
Exit Slip 5. True or false. The rate of the below
reaction can be measured as the increase in NH3. 2NH3 à N2 + 3H2
True, because NH3 is the product. 5. True, because NH3 is the reactant. False, because NH3 is the reactant. False, because NH3 is the product.
Review: What is a chemical reaction? Chemical reactions are… when atoms react to produce a molecule/compound
F + F à F2 Reactants
Products
F
F
F2
What is reaction rate? Reaction rate is…
What is your heart rate?
the speed of a chemical reaction.
Fe + O2 à Fe2O3
CH4 + O2 à CO2 + H2O
Slow…
Fast!
Product Product or or reactant? reactant?
What is reaction rate? Reaction rate can be measured in two ways: 1. How fast the reactants disappear How fast the products appear reactant
12:00pm What if the rate was faster?
product
12:30pm
Example #1 What are two different ways to describe the below chemical reaction?
1. How fast the
disappear
amount
The decrease in the concentration of the reactants
How fast the
appear
The increase in the concentration of the products
Example #2 What are two different ways to describe the below chemical reaction?
CH4 + O2 à CO2 + H2O reactants
The decrease in the concentration of CH4 and O2 The increase in the concentration of CO2 and H2O products
Example #3 True or false (and if false, correct it).
H2O2 à O2 + H2 The rate of the above reaction can be measured as the increase in H2 and H2O2.
False
Exit Slip 1. What is the simple definition of reaction rate? a. the amount of kinetic energy in a substance b. the number of products in a reaction c. the amount of energy needed to change a substance from one phase to another d. the speed of a reaction
Exit Slip 2. What is the measurable definition of reaction rate?
a. b. c. d.
The increase in the concentration of the reactants The decrease in the concentration of the reactants The decrease in the concentration of the products None of the above
Exit Slip 3. If the rate of below reaction was faster, which would be a true statement.
a. the concentration of squares in the middle box
would be higher b. the concentration of squares in the middle box would be lower c. there would be no change to the reaction d. the concentration of circles in the middle box would be lower
Exit Slip 4. Which of the following describes the rate of the chemical reaction,
H2 + O2 à H2O an increase in the concentration of H2O and H2 with time an increase in the concentration of H2O with time
4. an increase in H2 and O2 with time a decrease in H2O and O2 with time
Exit Slip 5. True or false. The rate of the below
reaction can be measured as the increase in NH3. 2NH3 à N2 + 3H2
True, because NH3 is the product. 5. True, because NH3 is the reactant. False, because NH3 is the reactant. False, because NH3 is the product.
