1.Compare the number of electrons in an ion of Na to an atom of Na. 2.Explain, in terms of electrons...

1. Compare the number of electrons in an ion of Na to an atom of Na.

2. Explain, in terms of electrons and energy, how ions emit light.

3. Explain, in terms of electrons, why the noble gases are non-reactive .

4. Define orbital.

Name: ______________Do Now 3/18/13

Chemical EquationsNOTES

When reactants are converted into products, a chemical reaction has occurred. When a reaction is represented by symbols,

it is called a chemical equation.In chemistry we represent the equal sign as

an arrow.The materials we start with are the

reactants.The arrow represents the reaction or what is yielded.

The materials that are made from a reaction are called the products.

Equations

6 + x = 14

C + O2 CO2

C + O2 CO2

Reactants Products

Yields orProduces

1 C Atom + 2 O Atoms = 1 C Atom + 2 O Atoms

NOTES

Law of Conservation of Matter (or Mass)

Matter cannot be created nor destroyed under ordinary chemical reactions.

Atoms cannot be created nor destroyed in a chemical equation.

NOTES

H2 + O2 H2O

Rules for Balancing Equations

• You cannot change formulas or subscripts

• Balancing atoms NOT molecules

• Can only add coefficients in front of formulas

H2 + N2 NH3

NOTES

H2 + N2 NH3

H2 + N2 2NH3

2 1

2 6

3H2 + N2 2NH3

6 Atoms of H 2 Atoms of N 2 Atoms of N 6 Atoms of H

NOTES

3 Moleculesof Hydrogen

1 Moleculeof Nitrogen

2 Moleculesof Ammonia≠Not Balancing Molecules

Balancing Chemical EquationsNOTES

• Balance one element (or ion) at a time

• Have a system

• Check everything again when you’re done balancing

C + Cl2 CCl4

NOTES

CO + H2 CH3OH

NOTES

CS2 + O2 CO2 + SO2

NOTES

CaCl2 + Cr(NO3)3

Ca(NO3)2 + CrCl3

NOTES

Naming

Remember, the positive ion always comes first followed by the negative ion

When it is just the negative ion alone, the name ends in –ide NaCl Sodium Chloride

If the name ends in something other than –ide, check your reference table

Naming Once you have the two pieces that are involved in

the compound, determine their charges (from the periodic table) and CRISS CROSS

Lithium Phosphide

Li P+1 -3

Li3P

Things to Remember:• Formulas First

• Roman Numerals tell you the charge of the ion • Criss-Cross oxidation states for subscripts• Diatomic Elements (I2, Br2, Cl2, F2, O2, N2, H2)• these are never just one atom

• Balance the equation with CoefficientsHydrogen reacts with Chlorine to make Hydrogen Chloride.

H2 + Cl2 HCl2

NOTES

Zinc + Silver Nitrate yields Zinc Nitrate

+ Silver

Write correct formulas (subscripts) and balance the following equations (coefficients)

NOTES

Barium Chloride + Sodium Sulfate

yields Barium Sulfate + Sodium

Chloride

Mr. Marbley mixes a sample of copper with a sample of sulfur in a beaker. The product is determined

to be copper (I) sulfide.

Mr. Abdalla mixes a sample of copper with a sample of sulfur in a beaker. The product is determined


Mr. Williams mixes a sample of copper with a sample of sulfur in a beaker. The product is determined


Mr. Howell mixes a sample of copper with a sample of sulfur in a beaker. The product is determined


Today’s Agenda1.Do Now (5 minutes)

a. Gather papersb. Hand in homeworkc. Try the regents problems

2. Mini Lessons:a. One half of class will do reactions labb. Rest of class will do interval reflectionc. SWITCH

3.Types of Chemical Reactions a. Notesb. Combustion Demonstration

Lab Procedure

1.Place ONE tablet in the balloon.2.Crush the tablet up.3.Fill the flask with 100 mL of warm water.4.Place the balloon on the top of the flask. DO NOT

dump the contents of the balloon into the flask.5.Find the mass of the flask, water, balloon, and tablet.6.Leaving the set-up on the scale, tip the balloon up so

the tablet falls into the water.7.Once the reaction stops, find the final mass of the set-

up.

Types of Chemical Reactions

Gives you the ability to predict what the

products will be when you mix two

reactants

NOTES

CombustionA hydrocarbon + O2 CO2 + H2O

2CH4 + 4O2 2CO2 + 4H2O

NOTES

Balancing Combustion Reactions

C2H6+ O2 CO2+ H2O

NOTES

Always balance Oxygen LAST

SynthesisNOTES

2 or more substances combine to form a more complex substance

A + B AB

Putting Puzzle Pieces Together

Synthesis Reaction

Fe + S FeS

2Mg + O2

H2O + SO3 H2SO4

2MgO

Solving Synthesis Reactions

Formula Writing In ionic bonds, an electron is transferred

between the atoms. Example:

Na Cl-1+1

Formula Writing

We can get the charge of an atom by looking at the periodic table.

What is the charge of a phosphorous ion?

What is the charge of a magnesium ion?

What are the charges of the ions Lithium and Fluorine?

Formula Writing

Once we have the charges, we crisscross the numbers to the subscript position.

Na Cl-1+1

Formula Writing

So the final formula for sodium and chlorine is just

NaCl

What is the formula for Na and Br?

What is the formula for Mg and Cl?

What is the formula for Rh and O?

Solving Equations So now we can write formulas We can identify synthesis reactions Lets put it all together.

H2 + 02 ????

Solving Equations

H2 + 02

Step 1: Look up the oxidation states for each element on the periodic table.

Solving Equations

H2 + 02

Step 2:Crisscross

Solving Equations

H2 + 02

Step 3: Rewrite

Solving Equations

H2+ 02

Step 4: Balance the Equation

H2O

Solve the following equation Na + F2 ???

Solve the following equation H2 + P ???

Solve the following equation Sr + N ???

NOTES

Decomposition1 substance breaks down into 2 or more simpler substances

AB A + B

Breaking Apart a Puzzle

Decomposition Reaction

FeS Fe + S

2NaCl

CaCO3 CaO + CO2

2Na + Cl2

Decomposition Reactions

Decomposition reactions are the same as synthesis reactions, only in reverse.

2H2 + O2 2H2O2H2O 2H2 + O2

Diatomic Atoms

When breaking a compound apart, you must remember that not all elements stay alone.

Elements that naturally bond with themselves are called Diatomic

H2 O2N2

Br2I2

F2

Cl2

I2 Br2ing Cl2ay F2rom O2ur N2ew H2ouse

Decomposition Reactions

NaCl

SrF2

Practice: Complete the following decomposition reactions

1. MgBr2

2. Na2O

3. HCl

NOTES

Single Replacement1 substance in a compound replaces another.An element reacts with a compound.

AB + C AC + BAB + C CB + A

Sharing among Children

Single Replacement Reaction

Why do single replacement reactions

occur?A more reactive

element replaces a less reactive element

NOTES

Zn + 2HCl ZnCl2 + H2

2Na + CuSO4 Na2SO4 + Cu

Cl2 + 2KBr 2KCl + Br2

Single Replacement Reactions

In a single replacement reaction, one element replaces another in a compound.

Sr + 2HCl H2 + SrCl2

Formulas

Remember, the first element in a compound’s formula is the cation (positively charged ion). The second element in a compound’s formula is the anion (negatively charged ion)

Who to Replace?Step 1: What is the potential charge on the

single element?Step 2: Which element in the compound has

the same type of charge?

Be + NaCl 2+ 1+ 1-

BeCl2 + Na

Complete the following reaction:

Li + NaCl

Complete the following reaction:

O2 + NaCl

But will it happen? In order for one element to replace another, it must be higher on Table J than

Check Your Homework… Any Questions?

5. 2Na + 2HOH H2 + 2NaOH

6. B + 3KF 3K + BF3

7. Ba + BaS Ba + BaS 8. Ca + 2HOH H2 + Ca(OH)2

NOTES

Double Replacement2 substances in a compound “switch” partners.A compound reacts with a compound.

AB + CD AD + CB

Trading

Double Replacement Reaction

Why do double replacement reactions

occur? One of the products must form as a gas, a

precipitate or as water

NOTES

Also known as…ionic reaction or solution reaction

NaCl + AgNO3 NaNO3 + AgCl

2K3PO4 + 3CaS Ca3(PO4)2 + 3K2S

Double Replacement Reactions

In a double replacement reaction, two ions switch places in two compounds.

Na F Li Cl

Double Replacement ReactionsOnce you have identified which two will switch (by looking at the charges), complete the switch and rewrite the formula.

Na N+ MgO 3

Double Replacement Reactions

KF + SrO

Practice:

NaCl + BeF2

Practice:

MgO + KCl

Practice:

BaBr2 + K2O

Polyatomic IonsPolyatomic Ions are multinuclear ions that can be treated as a group of atoms with a charge.

K CN Sr SO3

1+ 1- 2+ 2-1+1-2+ 2-

2 2( )

Complete:

Ba(NO3)2 + K2C2O4

Complete:

NaHCO3+ HCl

Using Balanced Equations

What we know…

Balanced equations follow the law of conservation of mass (whatever I start with I have to end with)

In order to balance an equation, we place coefficients in front of the formulas

Formulas represent groupings of atoms that are bonded together

Using Ratios

Consider the ratio 2 leaves : 1 plant

If I have 3 plants, how many leaves do I have?

2 leaves 1 plant

X leaves 3 plants=

Equations as Ratios Consider the following:

H2 + Cl2 2HCl

One Molecule of Hydrogen

One Molecule of Chlorine

Two Molecules of Hydrogen Chloride

There is a ratio between molecules

1 : 1 : 2

Equations as Ratios1H2 + 1Cl2 2HCl

How many HCl would be made if I used 3 molecules

of Cl2?

Equations as Ratios

1H2 + 1Cl2 2HCl

How many H2 would be needed if I made 8 molecules of HCl?

Mole Ratios

The coefficients of balanced equations also represent moles.

What is a mole? A mole is a number of particles just like a

dozen is 12 particles.

1H2 + 1Cl2 2HCl

1 mole = 6.023 x 1023 particles

Mole-Mole Problems

Instead of talking about

molecules, we simply switch to thinking about

moles.

How many moles of Cl2 is needed to make 10 moles of HCl?

1H2 + 1Cl2 2HCl

How many moles of HCl can be made using 6 moles of H2?

1H2 + 1Cl2 2HCl

How many moles of Cl2 are used in the production of 4 moles of HCl?

1H2 + 1Cl2 2HCl

1H2 + 1Cl2 2HCl

How many moles of HCl would be made if I used 3

moles of Cl2?

Consider: 3H2 + N2 2NH3

How many moles of NH3 are made from 6 moles of H2?

Consider: 3H2 + N2 2NH3

How many moles of N2 are used with 9 moles of H2?

Molar Mass

What we know…

Balanced equations follow the Law of Conservation of Mass

Equations can represent the ratio of molecules or moles involved in a reaction

A mole is a number of particles (6.022 x 1023)

Measuring Moles We do not have an

instrument that measures the number of moles of a substance.

Instead of measuring moles, we can measure mass and convert to moles

3 Moles of H2O

48 grams of H2O

Molar Mass The atomic mass unit was developed

using our understanding of a mole. Therefore, the molecular mass of a

molecule in amu is equal to its molar mass in grams. 0H2O

1 x 16 amu2 x 1 amu

= 16 amu= 2 amu

18 amu+

18 grams1 M

ole…

What is the molar mass of CH4?

What is the molar mass of NO2?

Using Molar Mass There are times when we want to know

how many particles are involved in a reaction

By using the molar mass, we can convert between moles (a number of particles) and mass.

Converting Moles to Grams

The mass of one mole of a substance is known as its molar mass

We can convert moles to grams using the formula

Moles = grams gram formula mass

How many grams does 2 moles of CO2weigh?

How much does 3 moles of H2O weigh?

Converting Mass to Moles In order to convert between mass and

moles, we can use the same formula as before.

How many moles is 36 grams of water?

How many moles is 48 grams of H2O?

Collision Theory

What we know… A reaction is when elements or compounds interact

to produce new combinations of elements and compounds.

Reactions occur when molecules collide (sometimes…)

Rate is another way of saying “how fast” something changes

Collision Theory

Consider the reaction CO(g) + NO2(g) CO2(g) + NO(g)

In order for a reaction to occur, the carbon monoxide and nitrogen dioxide gas particles need to come together

But it is more than just coming together, they need to have specific conditions

Collision TheoryIn order for a reaction to occur, the

two particles need to come together with the correct amount of energy

and the correct orientation.

Collision Theory

Correct Energy: Particles need to collide with enough energy to overcome the activation energy of the reaction

Correct Orientation: Particles need to collide with the correct positioning to allow for the correct bonds to be made.

Ways to Increase Rate

There are four means to which the rate of a reaction can be increased: Nature of the Reactants (some are more

reactive) Concentration (the amount of particles in

solution) Surface area (the number of particles available

to react) Temperature (how fast the particles are

moving)

Nature of Reactants

Consider Table J, some elements are more reactive than others

This can be due to the… Electronegativity (how much it wants the

electron in a bond) Electron Configuration (how close it is to

achieving a stable 8) Ionization Energy (how hard it is to remove the

electron)

Concentration

As the number of particles increases, the chance of an effective collision increases

Just like cars on a road, the more cars there are, the better the chance is to get into an accident

Surface Area The more substance that is exposed to collisions,

the faster (more collisions) the reaction will go Surface area is increased by… grinding, breaking

up, crushing, stirring, shaking, swishing…

Temperature Temperature is a measure of the particle

movement As we increase temperature, we increase

movement and increase the number of collisions For many reactions an increase in temperature

increases the rate of the reaction

LeChatelier’s Principle

What we must know…

A system is at equilibrium when the rates of change are equal

When a stress is applied to the system, the system will rebalance.

When concentration is changed, the system will shift to use up the added material


3H2 + N2 2NH3

By adding more H2, we have more collisions between H2 and N2

More collisions drives the reaction forward


3H2 + N2 2NH3

By adding more NH3, we have more chances for decompositionMore decomposition drives the

reaction in reverse

CH4 + 2O2 2H2O + CO2

an increase in H2O will…

1. Shift the reaction left2. Shift the reaction

right3. Cause no change

What could be done to shift the following reaction to the left?

H2 + I2 2HI1. Increase the

concentration of I22. Increase the

concentration of H2

3. Decrease the concentration of HI

4. Increase the concentration of HI

CH4 + 2O2 2H2O + CO2

an increase in oxygen will… 1. Cause the reaction to

shift left with the production of H2O

2. Cause the reaction to shift left with the production of CH4

3. Cause the reaction to shift right with the production of H2O

4. Cause the reaction to shift right with the production of CH4

Changes in Pressure/Volume

When we increase the pressure or decrease the volume, we push the particles closer together

This results in more collisions

Changes in Pressure/Volume

3H2 + N2 2NH3A decrease in pressure will cause

the system to shift towards the side with more molecules

Coefficients as Moles

Remember, the coefficients of the equation represent a mole ratio of molecules and atoms.

2C2H6 + 7O2 6H2O + 4CO2

Which side has more moles of gas?

Consider:2C2H6 + 7O2 6H2O + 4CO2

if the pressure is increased…

1. The reaction will shift towards the left

2. The reaction will shift towards the right

Consider:2C2H6 + 7O2 6H2O + 4CO2

if the volume is increased…

1. The reaction will shift towards the left

2. The reaction will shift towards the right

Consider: 2H2 + O2 2H2OIf the pressure is decreased

1. The reaction will shift to the left

2. The reaction will shift to the right

Consider: 2H2 + O2 2H2OIf the volume is increased

1. The reaction will shift to the left

2. The reaction will shift to the right

Changes in Temperature

Exothermic Reaction is when energy is given off

and Endothermic Reaction is when energy is absorbed

We can include the heat in a chemical reaction

Heat + A + B C + D or A + B C + D + Heat

Endothermic Exothermic


In an equilibrium system, if the forward reaction is exothermic, the reverse reaction will be the opposite, endothermic

2H2 + O2 2H2O + HeatExothermi

cEndother

mic


If we add heat to the system, are we helping the endothermic or exothermic reaction?

2H2 + O2 2H2O + HeatAdding heat favors the endothermic reaction

The reverse reaction is favored. Reaction shifts to the left.


By removing heat from the system (cooling it down) we favor the exothermic reaction.

Heat + CuCO3 CuO + CO2Exothermic

If the following system was cooled, the equilibrium will…

2H2 + O2 2H2O + Heat

1. Shift in the forward direction

2. Shift in the reverse direction

Adding heat to the following reaction will…

Heat + 2HI H2 + I21. Shift to the left,

favoring the exothermic reaction

2. Shift to the right favoring the exothermic reaction

3. Shift to the left favoring the endothermic reaction

4. Shift to the right favoring the endothermic reaction

In Summary

Concentration, shifts away from increasePV = Less moleculesPV = More Molecules

Adding heat favors endothermicCooling favors exothermic

Molar Mass

What we know…

Balanced equations follow the Law of Conservation of Mass

Equations can represent the ratio of molecules or moles involved in a reaction

A mole is a number of particles (6.022 x 1023)

Measuring Moles We do not have an instrument that measures the number of moles of a substance.

Instead of measuring moles, we can measure mass and convert to moles

3 Moles of H2O

48 grams of H2O

Molar Mass The atomic mass unit was developed using our

understanding of a mole. Therefore, the molecular mass of a molecule in

amu is equal to its molar mass in grams.

H2O1 x 16 amu2 x 1 amu

= 16 amu= 2 amu

18 amu+

18 grams1 M

ole…

What is the molar mass of CH4?

What is the molar mass of NO2?

Using Molar Mass There are times when we want to know how many

particles are involved in a reaction By using the molar mass, we can convert between

moles (a number of particles) and mass.

Converting Moles to Grams

The mass of one mole of a substance is known as its molar mass

We can convert moles to grams using the formula Moles = grams

gram formula mass

How many grams does 2 moles of CO2weigh?

How much does 3 moles of H2O weigh?

Converting Mass to Moles In order to convert between mass and moles, we

can use the same formula as before.

How many moles is 36 grams of water?

1.Compare the number of electrons in an ion of Na to an atom of Na. 2.Explain, in terms of electrons...

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