Chemical Reactions

Chemical Reactions Study Guide• Chpt. 9.4 Acids and Bases

• Chpt. 11: Balancing, Classifying, and Predicting Chemical Reactions

• Chapter 17.1: Thermochemistry (pg. 505-506)

• Chpt. 18.1: Reaction Rates

Chemistry (2/25)

• Acid/Base Quiz• Interpreting and Balancing chemical equations

Due: • Acid/Base Nomenclature worksheet for partial

credit

Chemical Reactions Objectives1.Classify and name compounds in chemical reactions2.Describe chemical reactions in word and chemical

equations.3.Balance chemical equations based on the Law of

Conservation of Mass.4.Identify and classify types of chemical reactions

and energy changes involved.5.Predict products and energy changes in a chemical

reaction. 6.Identify and test factors that affect the rate of

chemical reactions.

Chemistry (2/26)Infinite Campus Update: • Acid/Base Nomenclature Worksheet (10pts.)• Acid/Base Quiz (15pts.)*Check infinite a lot of missing assignments!*

Objectives:• Interpreting and Balancing chemical equations

Homework: • Check for missing assignments on infinite campus• Balancing chemical equations worksheet

Chemical Reaction Pre-Test1. What is a chemical reaction?2. If matter is conserved during a chemical reaction, how is

it new matter is “created”?3. Complete the questions below on the following word

equation: Fe(s) + O2 (g) ----> FeO (s) a. Give an example of a reactant from this reaction.b. Give an example of a product from this reaction. c. Balance the chemical equation if needed. d. Circle the type of chemical reaction you think this

represents. synthesis decomposition replacement neutralization combustion

Chemical Reactions• Substances chemically interact to form different

substances. • A substance can be an element or a compound.

• Chemical bonds are broken and created.

Example: Fe(s) + O2 (g) ----> FeO (s)

Chemical Equations Fe + O2 ------> FeO

Reactants:

• Starting substances.• Chemically interact with one another.• Usually located to the left of the arrow.Products:• Ending substances.• Substances formed from the chemical reaction.• Usually located to the right of the arrow.

Chemical Equations Fe(s) + O2 (g) ------> FeO (s)

Abbreviations for state of matter in an equation.• (s)= substance in solid state• (g)= substance in gaseous state• (l)= substance in liquid state• (aq)= substance dissovled in water. (aqueous solution)

Law of Conservation of Mass Fe(s) + O2 (g) ------> FeO (s)

• Are atoms destroyed or created during a chemical reaction?

• No, they are just rearranged to produce new substances.

Law of Conservation Of Mass

• Matter is not created or destroyed.

• Matter is just rearranged.(mass of reactants = mass of products)

That is why it is important to balance chemical equations.

Law of Conservation of Mass Fe(s) + O2 (g) ------> FeO (s)

Balancing Chemical EquationsWhy? Observe the Law of Conservation of Mass

Rules: 1. Add coefficients in front of substances, do NOT

change subscripts.

2. First balance elements that only appear once on each side of the equation.

3. Make sure coefficients are expressed in lowest terms.

Chemistry (2/27)Objectives:• Interpreting and Balancing chemical equations• Review acid/base quiz

Homework: • Balancing equations worksheet(due Thursday)• Law of Conservation of Mass pre-lab qts. and hypothesis• Review acids/bases nomenclature• Check for missing assignments in infinite campus

Lab: Law of Conservation of Mass Lab: (Thursday)

Law of Conservation of Mass LabHomework: • Read through the background and procedures

section.• Complete pre-lab questions and hypothesis.

Balancing Chemical Equations a. K + MgCl2 ---------> KCl + Mg

b. Ag2O ---------> Ag + O2

c. CH4 + O2 -------> CO2 + H2O

Chemical Equations

Chemistry (2/28)Objectives:• Interpreting and Balancing Chemical Equations• Validate the Law of Conservation of Mass with scientific

evidence.

Due Today: • Balancing chemical equations worksheet (turn in tray)• Law of Conservation of Mass pre-lab qts. and hypothesis

Homework: • Balancing Chemical Equations practice problems (Fri.)• Check for missing assignments in infinite campus

Balancing Chemical Equations

Dihydrogen monoxide + sodium (bicarbonate) ---> carbon dioxide + sodium hydroxide + dihydrogen monoxide

Law of Conservation of Mass LabPurpose: Validate the Law of Conservation of Mass

Lab Reminders: • Follow ALL lab procedures carefully.• Use the same balance for all measurements.

Acid/Base Nomenclature Quiz

Chemistry (3/4)Infinite Campus Update:• Conservation of Mass Lab (12pts.)• Balancing Chemical Equations (10pts)Objectives: • Balancing Chemical Equation Quiz• Classifying Chemical Reactions• Discuss Law of Conservation of Mass LabHomework: (Due Wed.)• Balancing Chemical Equations Worksheet• Classifying Chemical Reactions Worksheets

Chemical Reactions Objectives1. Identify and classify types of chemical reactions.

2. Identify energy changes involved with chemical reactions.

3. Predict products and energy changes in a chemical reaction.

Chemistry (3/6)Infinite Campus Update:• Balancing Chemical Equations Quiz (14pts.) Due Today:• Balancing Chemical Equation Worksheet (10pts.)Objectives: • Classifying Chemical Reactions• Identify energy changes associated with chemical

reactions• Discuss Balancing Chemical Equation QuizHomework: (Due Wed.)• Classifying Chemical Reactions Worksheets • Chemical Reaction Lab (pre-lab qts.)

Chemistry (3/6)Infinite Campus Update:• Balancing Chemical Equations Quiz (14pts.) Objectives: • Address qts. over Balancing Chemical Equation Quiz• Address qts. over Balancing and Classifying wks

(homework) • Discuss Neutralization Reaction • Introduce Chemical Reaction LabHomework: (Due Wed.)• Chemical Reaction Lab (pre-lab qts.)

Chemical Reaction Lab

Purpose: To perform and observe eight chemical reactions in the lab.

Homework: Read the introduction, background, and

procedures section; then answer the pre-lab questions on the front. (1-9)

Balancing Chemical Equation Quiz

Types of Chemical Reactions

1. Synthesis (R+ S ----> RS)2. Decomposition (RS------> R+ S)3. Single Replacement (T+ RS ---> TS + R)4. Double Replacement (R+S- + T+U- ---> R+U-+ T+S-)5. Combustion (CxHx + O2 ----> CO2 + H2O)

6. Neutralization (Acid + Base--> H2O + Salt)

(type of double replacement reaction)

Synthesis (Combination) Reaction

• 2 or more substances chemically combine to form a single substance.

• R+ S ----> RS + energy

• More energy is released at the end of the reaction then is needed to start the reaction.

(energy released by surroundings > energy absorbed by system)

Decomposition Reaction

• A compound breaks down into simpler substances.

• RS + energy ----> R + S

• More energy is required to start the reaction then is released at the end of the reaction.

(energy absorbed by system > energy released to surroundings)

.

Single Replacement Reaction

• An element replaces another element in a compound.

• T+ RS ---> TS + R + energy

• Usually energy of surrounding > energy of system

Double Replacement Reaction

• Exchange of cations between two ionic compounds. • R+S- + T+U- ---> R+U-+ T+S- + energy

• Usually energy of surrounding > energy of system

Combustion Reaction

• Fuel (CHO) reacts with oxygen to produce predictable substances and energy.

• CxHx(Ox) + O2 ----> CO2 + H2O + ENERGY

• Always energy of surroundings > energy of system

Neutralization • An acid and a base react to produce predictable

products. • Changes the pH to 7 (neutral).

Acid + Base -------> H2O + Salt(ionic compounds)

Salt: The cation comes from the base and the anion from the acid.

Ex. Na(OH) + HCl NaCl + H2O

Chemistry (3/11)Due: • Classifying and Balancing Chemical Equations wksht• Pre-lab questions(1-9) from Chemical Reaction Lab

Objectives:• Chemical Reaction Lab

Homework: • Turn in 3rd qtr. missing assignments for partial

credit.(Deadline: Wed. 3/13)

Chemical Equations to LabWrite the reactants for each reaction, and then predict

what type of reaction you think you are going to observe.

1. Mg + O2 ------>

2. Mg + HCl ----> 3. (NH4)2(CO3) ----->

4. Ca(CO3) + HCl ---->

5. Zn + CuCl2 ---->

6. CuCl2 + Na3(PO4) --->

7. HCl + Na(OH) ----> 8. C2H6O + O2 ----->

Chemical Reaction Lab (3/11)

Purpose: • Predict the type of reaction for each experiment. • Perform, observe, and record data for each

chemical reaction.

Chemistry (3/12)Infinite Campus Update:• Classifying and Balancing Chemical Rxtns. (10pts.)

Objective: • Chemical Reaction Lab

Homework:• Balancing reactions and establishing a conclusion

for the lab.

Chemical Reaction Lab (3/12)

Purpose: • Complete chemical reaction lab.• Predict products of each reaction.• Balance each chemical reaction.

Chemistry (3/13)Objectives• Predict products of each reaction from the lab• Balance equations(if needed) and establish

conclusion for lab.

Homework:• Complete chemical reaction lab

Chemical Equations to LabPredict the products of each reactant.1. Mg + O2 ------> MgO

2. Mg + HCl ----> 3. (NH4)2(CO3) -----> NH3 + CO2 + H2O

4. Ca(CO3) + HCl ----> CaCl2 + H2O + CO2

5. Zn + CuCl2 ---->

6. CuCl2 + Na3(PO4) --->

7. HCl + Na(OH) ----> 8. C2H6O + O2 ----->

Chemical Equations to Lab

Just need to check and see if they are balanced. 1. Mg + O2 ------> MgO

2. Mg + HCl ----> MgCl + H2

3. (NH4)2(CO3) -----> NH3 + CO2 + H2O

4. Ca(CO3) + HCl ----> CaCl2 + H2O + CO2

5. Zn + CuCl2 ----> ZnCl2 + Cu

6. CuCl2 + Na3(PO4) ---> Cu3(PO4)2 + NaCl

7. HCl + Na(OH) ----> H2O + NaCl

8. C2H6O + O2 -----> CO2 + H2O

ConclusionA summary that includes the following: • Identify and explain which reactions from the lab

were synthesis, decomposition, single replacement, double replacement, neutralization, combustion.

• Based on the data section explain which reactions were exothermic and endothermic.

• Which reaction(s) did you like the best and why?

• What did you learn from this lab? (be specific)

Chemistry (3/14)Due Today:• Chemical Reaction Lab

Objectives: • Classifying reactions• Predicting products• Balancing chemical equations

Homework: • Predicting products and balancing equations wks.

(Chemistry 3/15)Infinite Campus:*Chemical Reaction Lab (26pts. )-3rd qtr.*

Objectives:• Classify reactions• Predict products• Balance Chemical Equations

Homework:• Complete Predicting Products Worksheet.• Complete internet enrichment problems.

Monday: Quiz over chemical reactions. Study!

Chemical ReactionsPredict the products for each reaction and balance if needed.

a. 3Ca + N2 --------> Ca3N2 (synthesis)

b. Cu2S -------> 2Cu + S (decomposition)

c. 2NaBr + F2 ------> 2NaF + Br2 (single replace)

d. CH4 + 2O2 -----> CO2 + 2H2O (combustion)

e. H2(CO3) + 2K(OH) -----> K2(CO3) + 2H2O (neutralization)

Chemistry (3/18)Objectives:• Classifying, Balancing, Predicting Products• Activity Series Table and Single Replacement

Homework:• Activity Series Pre-Lab reading and hypothesis• Chemical Reaction Quiz (Wednesday)• Work on study guide (Test Monday)

Chemical Reactions: Bell Ringer1. What are the coefficients that will balance the

chemical equation below? AlCl3 + Na(OH) ----> Al(OH)3 + NaCl

a. 1,3,1,3b. 3,1,3,1c. 1,1,1,3d. 1,3,3,12. What type of chemical reaction is expressed above?

3. Predict the product(s) and balance if needed: Ba (s) + O2 (g) ---------->

Predicting Products

Predicting Products Gallery Walk

Objective: • Classify Type of Reaction• Predict Products• Balance Equation

Gallery Walk: Predicting Products

At each station complete the following: a. Predict the type of reactionb. Predict the productsc. Balance the chemical equation if needed

Chemistry (3/19)Objectives:• Activity Series Table and Single Replacement

Homework:• Activity Series Lab conclusion and post-Lab

questions• Chemical Reaction Quiz (Wednesday)• Work on study guide (Test Monday)

Activity Series Lab Hypothesis CuCl2(aq) Ag(NO3) HCl (aq) dH(OH) (l)

Copper (s)

Magnesium (s)

Zinc (s)

Calcium (s)

Chemistry (3/20)Objectives:• Chemical Reaction Quiz• Discuss Activity Series Lab• Discuss Endothermic and Exothermic Energy

Diagrams

Homework:• Complete Activity Series Lab• Energy Changes Worksheet• Work on Study Guide

Activity Series Lab

*After complete quiz, work on the following: Activity Series Lab:• Complete conclusion and post-lab questions.

Chemistry (3/21)Infinite Campus Update:• Chemical Reaction Quiz (16pts.)Due: Activity Series Lab

Objectives: • Interpreting Activity Series Table• Interpret energy changes in chemical reactions.• Identify and test factors that affect the rate of chemical

reactions.

Homework: Work on study guide.

Activity Series Table

*Study Guide Modification: omit qts. 18

Bell Ringer: Work on qts. 13 from study guide.

Thermochemistry • Study of energy changes during a reaction.

Energy Review Qts:• When observing a chemical reaction what is the

difference between the system and its surroundings?

• Energy always flows from ____ matter to _____ matter. (cold, hot)

Chemistry:3/22Infinite Campus:Chemical Reaction Quiz (16pts) Assignments Collected:Activity Series LabObjectives: • Interpret and classify energy changes in

reactions• Identify and predict how factors affect the

speed of a reaction.

Thermochemistry Energy changes that occur within reactions.

Endothermic Reactions Exothermic Reactions

Exothermic Reaction• Energy (H) absorbed < Energy (H) released. • The chemical reaction becomes cooler and its surroundings gets

warmer. • Test tube gets? • Energy is on the products side.• Examples: • combustion of fossil fuels (transportation)C8H18 + O2 -------> CO2 + H2O + energy

• cellular respiration in living organisms C6H12O6 + O2 ------> CO2 + H2O + energy

Endothermic Reactions• Energy (H) absorbed > Energy (H) released• Chemical reaction gets warmer and its

surroundings gets cooler. • Test tube gets ?• Energy is on the reactants side.Ex. Photosynthesis

Energy Diagram

(H)

(time)

Chemical Reaction Energy Diagram•Activation Energy (Ea): The minimum amount of energy needed for the reaction to occur.

H: Energy change between reactants and products. ( H = H products – H reactants)

Energy DiagramDoes this represent an endothermic or exothermic reaction?

(H)

(time)

Energy Diagram H reactant > H product Small activiation energy More energy will be released in this reaction

(H)

(time)

Energy Diagram

Activation Energy

Does this represent an endothermic or exothermic reaction?

(H)

(time)

Endothermic Energy Diagram

Activation Energy

• H reactant < H product•Large activation energy•More energy will be absorbed in this reaction

Thermochemistry Examples Classify the following examples as endothermic

(E) or (Ex) exothermic:1. If the surroundings gets cooler and the

system gets warmer.2. Ice cream melting. 3. Melted paraffin wax is left at room

temperature until it solidifies.4. AlCl3 ------> Al + Cl2 + energy5. A bright light is created when magnesium

reacts with oxygen.6. When hydrochloric acid reacts with

magnesium the test tube will get warm.

Chemical Reactions Rates• Reaction Rates = how fast the reactants

chemically change into the products. • Collision Theory: Reactant particles will form

products when reactants collide:- at the right position.- and exchange the right amount of kinetic energy.

Rates of Chemical Reactions

• What are factors that can affect the speed of a reaction?

Rates of Chemical Reactions

• What are factors that can affect the rates of reactions?

• Temperature• Concentration of Reactants• Surface Area of Reactants• Catalysts• Inhibitors

Temperature of Reaction

What if we increase the temperature of a reaction?

What if we decrease the temperature of a reaction?

Concentration

• Increase concentration of reactants?

• Decrease concentration of reactants?

Surface Area

• Increase surface area of reactants?

• Decrease surface area of reactants?

Catalysts

• Catalysts speed up reactions, but they are not apart of the chemical reaction.

Ex. Enzymes keep your body temperature around 37oC (98 oF) by speeding up important biological reactions.

Catalyst and Energy Change

Inhibitors

• Inhibitors slow down a chemical reaction, but are not apart of the reaction.

• Inhibitors bind to a catalyst and prevent it from speeding up a reaction.

Ex. Preservation of food. Antioxidants prevent foods from becoming stale or moldy.

Chemical Reactions Study Guide

• Chpt. 9.4 Acids and Bases

• Chpt. 11: Balancing, Classifying, and Predicting Chemical Reactions

• Chpt. 18.1: Reaction Rates

Chemical Reaction Study Guide