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

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 Chemistry Write 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.

Warm Up Write a balanced chemical equation for the following demo. Isopropyl alcohol (CH 3 ) 2 CHOH when ignited (Oxygen gas) combusts to form Carbon dioxide gas and water.

Observing 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? ppt crystal color gas fumes smoke temperature flames magnetic lsoundsound llightlight lsolid decompsolid decomp lexplosionexplosion lsolid dissol.solid dissol. lodorodor lelect. cond.elect. cond. lpH changepH change ldensitydensity lelectricityelectricity Go to next topictopic Moving On

Precipitate Formation Ag + + Cl -  AgCl Cr OH -  Cr(OH) 3 Ba 2+ + CrO 4 2-  BaCrO 4 return

Solid Decomposition (NH 4 ) 2 Cr 2 O 7 (s)  Cr 2 O 3 (s) + 4H 2 O(g) + N 2 (g) CuSO 4. 5H 2 O  CuSO 4 + 5H 2 O(g) 2NI 3  2 + 3I 2 2NI 3  N 2 + 3I 2 return

Gas Bubbles Ca + 2H 2 O  Ca(OH) 2 + H 2 (g) Cr + 2H +  Cr 2+ + H 2 (g) Mg + 2HCl  MgCl 2 + H 2 return

Fumes/Gas Formation Cu + 4HNO 3  Cu(NO 3 ) 2 + 2NO 2 + 2H 2 O 2H 2 O 2  2H 2 O + O 2 Zn + I 2  ZnI 2 return

Smoke 2Al + 3Br 2  2AlBr 3 2Na + Cl 2  2NaCl P 4 + 5O 2  P 4 O 10 return

Flames 2Na + Cl 2  2NaCl2CrO 3 + 3C 2 H 5 OH  Cr 2 O 3 + 3CH 3 CHO + 3H 2 O return

Light 2Fe + 3O 2  Fe 2 O 3 2CH 3 OH + O 2  2CO 2 + 4H 2 O 2H 2 + O 2  2H 2 + O 2  2H 2 O return

Temperature Change Ba(OH) 2. 8H 2 O + NH 4 Cl Thermite: Al + Fe 2 O 3 return

Color Change Cl 2 + 2I -  2Cl - + I 2 Cu + 4HNO 3  Cu(NO 3 ) 2 + 2NO 2 + 2H 2 O return

Crystal Formation/Solid Deposition Cu + 2Ag +  Cu Ag Zn + Sn 2+  Zn 2+ + Sn return

Solid Dissolution Mg(OH) 2 + 2HCl  MgCl 2 + 2H 2 O AgCl(s) + 2NH 3 (aq)  Ag(NH 3 ) Cl - return

Sound Oxidation of sugar Fireworks return

Explosion Dynamite Building Demolition Whale Removal return

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

Electrical Conductivity Ba(OH) 2 + H 2 SO 4 return

Density/Volume Sugar + H 2 SO 4 return

pH Change return

Magnetic Properties Fe + S 8 return

Generate Electricity Chemical reaction in the battery return

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 1 Zinc metal reacts with hydrochloric acid to produce hydrogen gas and zinc (II) chloride. Experiment 2 Dihydrogen 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 3 Calcium 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) + O 2 (g) 2 MgO (s)

Decomposition Reaction AB  A + B Ex. salt  metal + nonmetal 2 NaCl (s)  2 Na (s) + Cl 2 (g)

Single-Displacement Reaction A + BC  B + AC or A + BC  C + BA Ex. metal + acid  hydrogen + salt Zn (s) + 2 HCl (aq)  H 2 (g) + ZnCl 2 (aq) Ex. metal + salt  metal + salt Fe (s) + CuSO 4 (aq)  Cu (s) + FeSO 4 (aq)

Double-Displacement Reaction AB + CD  AD + CB Ex. acid + base  salt + water HCl (aq) + NaOH (aq)  NaCl (aq) + H 2 O (l)

Can you Classify the following picture reactions?

4 Types of Reactions Synthesis Decomposition Single Displacement Double Displacement

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. 2H 2 + O 2  2H 2 O Hydrogen reacts with oxygen to produce water. 2. 2H 2 O  2H 2 + O 2 Water decomposes to produce hydrogen and oxygen

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.

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, Fe 2 O 3, with carbon. The carbon is converted to CO 2. Write a balanced chemical equation for this reaction.

Helpful info Sulfuric Acid- H 2 SO 4 Ammonia- NH 3 Carbonic Acid - H 2 CO 3 Hydrofluoric Acid – HF Phosphoric Acid – H 3 PO 4

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. Cl 2 + KI  2. FeCl 3 + NaOH 

Single Displacement: Cu + AgNO 3

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 The 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

Predict whether a reaction occurs Pb + MgCl 2 Al + Cu(NO 3 ) 2 Practice

Group Quiz Na + H 2 O Ca + Fe(NO 3 ) 2 Ag + Mg(NO 3 ) 2 Zn + Cu(NO 3 ) 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