Warm Up

Watch the Demo of Copper with Nitric Acid. List several evidences for chemical reaction.

state_in_eqn.exe04m11vd4.mov

Chemical reactions are everywhere!

Chemical Reactions: the process by which the atoms of one or more substances are rearranged to form different substances.

Atoms are rearranged during the flash of lightning!

Chemical Equations

Reactants Products

Reactants: starting substances

Products: substances formed during the reaction

*Shows the direction in which the reaction progresses.

* means “yield” or “react to produce”

Chemical Equations

Symbols are used to show the physical states: solid(s), liquid(l), gas(g).

“aqueous” (aq) substance is dissolved in water

The Language of ChemistryWrite the chemical equation that corresponds to

the following reactions

Example

1. Solid calcium oxide reacts with water and yields calcium hydroxide solution.

2. Zinc metal reacts with a hydrogen sulfate solution to produce a zinc sulfate solution and hydrogen gas.

3. A potassium bromide solution reacts with chlorine gas to produce a potassium chloride solution and bromine gas.

Balancing Equations

Coefficient – the whole number out front of the formula- tells you how many of each molecule

Subscript – small number to the bottom right of an element- tells you how many atoms of that element are in the molecule.

Balancing Chemical Equations

1. Write a formula equation with correct symbols and formulas.

2. Count the number of atoms of each element on each side of the arrow.

3. Balance atoms by using coefficients.

4. Check your work by counting atoms of each element.

Balancing Chemical Equations

Practice Problems Sodium hydroxide decomposes to

produce sodium oxide and water.

Iron reacts with oxygen to produce iron(III) oxide.

Warm Up

Write a balanced chemical equation for the following demo.

Isopropyl alcohol (CH3)2CHOH when ignited (Oxygen gas) combusts to form Carbon dioxide gas and water.

Observing and Predicting ReactionsObserving and Predicting Reactions

How do we know whether a reaction occurs? What clues does nature offer? Make a list.

What clues does nature offer that a chemical reaction occurred?What clues does nature offer that a chemical reaction occurred?

ppt crystal color gas fumes smoke temperature flames magnetic

soundlightsolid decompexplosionsolid dissol.odorelect. cond.pH changedensityelectricity Go to next topic

Moving On

Precipitate FormationPrecipitate Formation

Ag+ + Cl- AgCl Cr3+ + 3OH- Cr(OH)3

Ba2+ + CrO42- BaCrO4

return

BaCrO4.mov.lnk

04m12vd1.mov.lnk

Solid Decomposition

(NH4)2Cr2O7(s) Cr2O3(s) + 4H2O(g) + N2(g)

CuSOCuSO44..5H5H22OO

CuSOCuSO44 + 5H + 5H22O(g)O(g) 03m14vd1.mov.lnk

2NI2NI33 N22 + 3I + 3I22 Vd05_005.mov.lnk

Chmvid06.mov.lnk volcano.mov.lnk

return

Gas BubblesGas Bubbles

Ca + 2H2O Ca(OH)2 + H2(g) Cr + 2H+ Cr2+ + H2(g)

Mg + 2HCl MgCl2 + H2

tums.mov.lnk

04m05vd1.mov.lnk

return

Fumes/Gas Formation

Cu + 4HNO3 Cu(NO3)2 + 2NO2 + 2H2O

2H2O2 2H2O + O2

Zn + IZn + I2 2 ZnIZnI22

04m11vd4.mov.lnk Chmvid03.mov.lnkreturn

Smoke

2Al + 3Br2 2AlBr3 2Na + Cl2 2NaCl P4 + 5O2

P4O10

04m02vd1.mov.lnk

04m04vd1.mov.lnk

Vd05_004.mov.lnk

return

Flames

2Na + Cl2 2NaCl 2CrO3 + 3C2H5OH

Cr2O3 + 3CH3CHO + 3H2O

A04-2-20.mov.lnk return

Light

2Fe + 3O2 Fe2O3

2CH3OH + O2 2CO2 + 4H2O

2H2H22 + O + O22 2H2O05m04vd1.mov.lnk

04m18vd2.mov.lnk

return

Temperature ChangeTemperature Change

Ba(OH)2.8H2O + NH4Cl

Thermite: Al + Fe2O3

Chmvid13.mov.lnk return

Color ChangeColor Change

Cl2 + 2I- 2Cl- + I2 Cu + 4HNO3

Cu(NO3)2 + 2NO2 + 2H2O

04m11vd4.mov.lnk

return

Crystal Formation/Solid DepositionCrystal Formation/Solid DepositionCrystal Formation/Solid DepositionCrystal Formation/Solid Deposition

Cu + 2Ag+ Cu2+ + 2Ag

Zn + Sn2+ Zn2+ + SnZn_sncl2.mov.lnk

04m16vd1.mov.lnk

return

Solid DissolutionMg(OH)2 + 2HCl MgCl2 + 2H2O

AgCl(s) + 2NHAgCl(s) + 2NH33(aq) (aq)

Ag(NHAg(NH33))22+ + + Cl+ Cl--

return

Sound

Oxidation of sugar

Fireworks

bang.mov.lnk

06m02vd1.mov.lnk

return

Explosion

Dynamite

Building DemolitionBuilding Demolition Whale RemovalWhale Removalreturn

Odor

Certain molecules, especially those containing sulfur or nitrogen, have distinctive odors.

return

Electrical Conductivity

Ba(OH)Ba(OH)22 + H + H22SOSO44

return

Density/Volume

Sugar + H2SO4

volcano.mov.lnk

return

pH Change

return

Magnetic PropertiesFe + S8

return

Generate Electricity Chemical

reaction in the battery

returnreturn

Lab- How do we know what gas is being produced?

Demo- Gas Collection by Water Displacement

Minimum of two trials of each reaction Work as pairs within your groups

While others are testing draw apparatus and write the general procedures

Lab- How do we know what gas is being produced?

Experiment 1Zinc metal reacts with hydrochloric acid to

produce hydrogen gas and zinc (II) chloride.

Experiment 2Dihydrogen dioxide in the presence of the

catalyst sodium iodide decomposes to produce oxygen gas and liquid water.

Lab- How do we know what gas is being produced?

Experiment 3Calcium Carbonate reacts with hydrochloric acid to produce a

gas. What gas is it? Design an experiment to identify the gas produced.

Include predictions. Get it signed off before you begin

If…and…then… If(hypothesis) and(test) then(prediction) If all chemistry students have memorized the element

names and symbols and they are asked to the name or symbol for any element then every student will answer every question correctly.

Lab- How do we know what gas is being produced?

What did you learn from Experiment 3? What gas is being produced?

Lab- How do we know what gas is being produced?

Experiment 4

Can we confirm this some other way?

Group Quiz

1. Hydrogen gas reacts with oxygen gas to produce water

2. Carbon monoxide gas reacts with oxygen gas to yield carbon dioxide gas.

3. Liquid dihydrogen dioxide decomposes to produce water and oxygen gas.

4. A calcium hydroxide solution reacts with a hydrogen sulfate solution to produce a calcium sulfate solution and water.

What do all Chemical Reactions have in Common?

All Chemical Reactions obey the Law of Conservation of Matter

Nothing can be created or destroyed.

(What goes in must come out.)

4 main types of chemical reactions

Synthesis or Combination Decomposition Single Displacement Double Displacement

Types of Chemical Reactions

Combination reaction• A + B AB• Ex. metal + oxygen metal oxide

2 Mg (s) + O2 (g) 2 MgO (s)

Decomposition ReactionAB A + BEx. salt metal + nonmetal

2 NaCl (s) 2 Na (s) + Cl2 (g)

Single-Displacement ReactionA + BC B + AC or A + BC C + BA

Ex. metal + acid hydrogen + salt• Zn (s) + 2 HCl (aq) H2 (g) + ZnCl2 (aq)

Ex. metal + salt metal + salt• Fe (s) + CuSO4 (aq) Cu (s) + FeSO4 (aq)

• Double-Displacement ReactionAB + CD AD + CB

Ex. acid + base salt + water• HCl (aq) + NaOH (aq) NaCl (aq) + H2O (l)

Can you Classify the following picture reactions?

1

2

3

4

4 Types of ReactionsSynthesis

Decomposition

Single Displacement

DoubleDisplacement

Some Practice

Write as many chemical reactions as you can think of using the following atoms and molecules as reactants.

Practice

Word Equations and reaction types identification

Classification of Chemical reactions

Individual Classify each type of reaction

Group Quiz Work as a group to write word equations

for each of the reactions

Classification of Chemical Reactions

Examples

1. 2H2 + O2 2H2O

Hydrogen reacts with oxygen to produce water.

2. 2H2O 2H2 + O2

Water decomposes to produce hydrogen and oxygen

Round Table – Balancing Chemical Equations

1. Balance the Equation

2. Write a complete sentence for each reaction including (atom/molecule) references to the coefficients.

Team

Iron can be obtained by reacting the naturally occurring ore hematite, Fe2O3, with carbon. The carbon is converted to CO2. Write a balanced chemical equation for this reaction.

Helpful info

Sulfuric Acid- H2SO4

Ammonia- NH3

Carbonic Acid - H2CO3

Hydrofluoric Acid – HF

Phosphoric Acid – H3PO4

Law of Conservation of Mass

Balancing synthesis and Decomposition Reactions Counting atom amu– atomic mass unit

Predicting Products

Identify the type of reaction Write the products of the reaction Balance the equation

Example.

1. Cl2 + KI

2. FeCl3 + NaOH

Single Displacement: Cu + AgNO3

Vd04_012.mov.lnk

Lab – Types of Reactions

9 experiments Work at an open station Demo Copper and Silver Nitrate

Predicting Products

Being able to write a chemical equation does not necessarily mean that the reaction will take place.

There is a way to predict whether a reaction will occur and what the products will be.

The Activity Series of Metals

Predicting Products Predicting Products The Activity SeriesThe Activity SeriesPredicting Products Predicting Products The Activity SeriesThe Activity Series

Matter tends to react in such a way that more reactive substances form less reactive substances.

Activity series: a list of metals organized according to their tendency to react.

Activity Series

The higher the metal on the activity series, the more active that metal.

The more active elements tend to be more stable in a compound than in elemental form

single_displ.exe.lnk

Predict whether a reaction occurs

Pb + MgCl2 Al + Cu(NO3)2

Practice

Group Quiz

Na + H2O

Ca + Fe(NO3)2

Ag + Mg(NO3)2

Zn + Cu(NO3)2

Objectives

Students will review types of chemical reactions.

Students will investigate the law of conservation of matter and its effect on chemical equations.

Students will learn to balance chemical equations