Unit 6 Mole and Stioch.

Unit 6 Starts

Tues:Panther Drill Review Problem5-10 min ReviewQuizEarly Finish = Word Search

Panther DrillPotassium Chlorate reacts to form Potassium chloride

and oxygen gas. Write the equation for this reaction, balance it, and state what type of reaction it is.

Skeleton Equation:KClO3 KCl + O2

Balanced ____KClO3 ___ KCl + ____O232 3

Wednesday

PD= Converions Modeling: How to us Dim AnaylisisPractice

TODAYToday: We will practice using dimensional

analysis to convert between units. This is a review of what we did in

Panther Drill

Convert 5 feet into cm. 1 inch = 2.54 cm Set up the conversions using dimensional analysis.

5ft x 12 in 2.54 cm = 1 ft 1 in

152.4 cm

Active Inspire Practice

Thurs

Panther DrillGuess how many activityPairs will list ways items are quantified other

than by the each.Notes Discussion on the moleExit ticket “Explain the mole is similar to a

dozen.”

Panther DrillThere are 50

paperclips in a box and 20 boxes in a case. If I have 2750 paper clips how many cases do I have?

TODAY1. 1 more dimensional

analysis problem2. Explain how to count

large numbers of small items w/out counting them individually

3. Meet the Mole.

Get with your partner

Make a list of different units there are to count items. EXAMPLES

Ream: 500 pieces of paper.

A gross: A gross of something = 144 of an item

Hint: How are things sold in the supermarket.

Active inspire

List our lists

1 Intro

We have seen how much easier it is to count small items such as paper clips by a larger unit rather than by the each.

That was easy compared to if you had to count the number of atoms of aluminum in a paper clip.

2 IntroChemist often have to find out how many atoms

or particles of an element or compound are in a sample. This would be nearly impossible with out a unit that would count a very small things w/ out counting each particle individually.

Chemists use the Mole

NO not either of these

3 IMPORTANT!!A mole or (mol) is the SI or scientific unit for

counting particles, atoms, or molecules.

The mole was defined in 1811 by an Italian scientist and lawyer named Avogadro. He figured out that there was 602,213,670,000,000,000,000,000 particles of anything in 1 mole of that item.

We use scientific notation = 6.02x 1023

This is called Avogadro’s number

4Look at the test tubes being past around you will

see that you can have moles of different kinds of particles.

Tube 1 has 1 mole of copper atomsTube 2 has 1 mole of water moleculesTube 3 has 1 mole of salt moleculesBeaker has 1 mole of sugar moleculesWhat do you notice about the moles of the

items, how are they different?

5Think about it this way

A mole of sugar molecules can look larger than a mole of salt molecules (even though they both contain 6.02x 1023 particles) because the molecules of sugar are larger than a salt molecules.

Just like a dozen marbles looks larger than a dozen than a dozen pennies, but the each have 12 items in them.

EXIT TICKETExplain the mole is similar to a dozen.

NAME:

Monday

Panther Drill

In your own words define a mole as it is used in chemistry.

What’s in a Mole

Remember the mole is the # of particles in a sample.

Avogadro's # says there are 6.02 x 1023 particles of any thing in a mole of a sample being measures

There are 3 different representative particles that a mole can count: Atoms, Molecules, and Formula units

In an element (H,Cl, Zn ect) it represents atoms

In a molecular compound such as water, sucrose, and carbon dioxide, the mole counts molecules.

In an Ionic Compound like NaCl, or Magnesium Oxide, the mole counts formula units

What is the representative particle in the following?

1. LiCl2. C12H22O11

3. BeH2

4. Mg5. PCl5

ATOMS

Formula Units

Formula UnitsMolecules

Molecules

Conversion Cheat SheetOn the index card provided or somewhere you won’t

lose it write down the following:

You can use this when doing conversions

Side 2 of Index Card

# of Moles = # of particles X ___1 mole __.

6.02 X 1023

particles

Finding the number of moles

Finding the number of particles

# of Particles = # moles X 6.02 X 1023 particles 1 mole

Side 1 of Index Card

Panther DrillWhat is the representative particle being counted by

the following:1. NaCl2. CO2

3. Fe4. H2SO4

Conversion moles to particlesConvert 3.50 moles of Sucrose to # of particles

3.50 moles x X 6.02 X 1023 particles = 1 mole

DO THE MATH:2.11 x 1024

Conversion (Particles to Moles)Convert 4.5 x 1024 atoms of Iron to moles of iron

What Conversion factor?# of Moles = # of particles X 1 mole ___.

6.02 X 1023 particles

Moles = 4.5 x 1024 atoms X 1 mole ___.

6.02 X 1023 atoms

DO THE MATH: 7.48 moles Fe

You practice now

You and your partner practice now

Partner A

1. 2.5 moles of Zn to # atoms

2. 2.9 x 1024 formula units of NaCl to moles

Partner B

1. 4.0 moles of CO2 to # molecules

2. 7.2 x 1023 formula units of Li2S to moles

Tuesday

Panther Drill

1) Convert 3.50 moles of Salt to # of particles

2) Which types of particles are you counting (atoms, molecules or formula units) in the compound salt?

Work on some mole conversions on your own

Get a WS and complete all 5 problems

Examples Moles = 4.5 x 1024 atoms X 1 mole _ = 7.48 moles Fe

6.02 X 1023 atoms# Particles: 3.50 moles X 6.02 X 1023 part. =

1 mole2.11 x 1024

molecules

Moles and Mass

Panther Drill

If 1 dozen eggs weighs 2.3 pounds, determine how much 5.5 dozen weigh.

5.5 doz1

2.3 lb 1 doz

X 5.5 X 2.3 lbs = 12.65 lbs=

Mass and the mole in single elements

A mole always contains the same number of particles; but moles of different substances have different masses.

Think about it like this: A mole is like a dozen.

A dozen bowling balls would have a different mass than a dozen eggs, but each one still has 12 items in it.

Lets look at the element Carbon1 mole of Carbon = 6.02 x 1023 atomsCarbon has an molar (atomic)mass

of 12.01 g

The mass of 1 mole of a substance = the molar mass

**The mass of 1 mole of an element can be found on the periodic table

12C

Carbon 12.01

Converting from # of moles to massLets look at a dozen jellybeans

1 dozen jellybeans = 35 gramsTHIS BECOMES OUR CONVERSION FACTOR

How many grams are there in 5 dozen jelly beans?

1 dz jelly beans5 dz Jellybeans 35 grams = __________ g175

Converting From Moles to Mass

The mass of 1 mole of carbon = 12.01 g

How many grams are there in 8 moles of carbon?

12.01 g C8 moles of C x1 mol C

=____________ g Cu96.08

Moles to Mass (2)

The mass of 1 mole of copper = 63.546 g

How many grams in 4 moles of copper:4 mol Cu = =____________ g Cu

1 mol Cu262.1865.546 g Cu

Converting Mass to Moles

You have 7.6 Grams of Boron (Atomic/Molar Mass 10.81)

Convert grams of Boron to moles of BoronConversion factor: 1 mole of boron = 10.81 gramsHow would you set up the conversion fraction?7.6 g B X 1

1 mol B10.81 g B

= ________mol B0.703

You Try

Partner A and BPARTNER A

How many moles are in 15 grams of lithium?

Partner BHow many grams are in 2.4 moles of sulfur?

Each student do their own problem and then explain how they got the answer to their partner

Partner A

How many moles are in 15 grams of lithium? (molar mass of lithium is 6.94 g/mole)

15 grams Li x

2.16 moles

1 mole = 6.94 grams

15/7 moles Li

Partner B

How many grams are in 2.4 moles of sulfur?molar mass of sulfur is 32 g/ mole

2.4 moles x 32.065 grams S 1mole S

76.956 g S

Practice Moles to Grams of AtomsHow many moles are in 22 grams of argon?

How many grams are in 88.1 moles of magnesium?

How many moles are in 2.3 grams of phosphorus?

How many grams are in 11.9 moles of chromium?

How many moles are in 9.8 grams of calcium?

Practice Moles to Grams of AtomsHow many moles are in 22 grams of argon?

How many grams are in 88.1 moles of magnesium?

How many moles are in 2.3 grams of phosphorus?

How many grams are in 11.9 moles of chromium?

How many moles are in 9.8 grams of calcium?

MONDAY

Panther DrillHow many moles are in 198.6 grams of potassium?198.6g K x

How many grams are in 12.3 moles of nitrogen?12.3 mol N

1mol .39.1 g K ___________ moles K

14.01 g N 1 mol N

___________ g N

5.08

172.32

Converting Grams to Moles to Particles2 ways to do this

1. Convert from grams to moles then separately convert from moles to particles.Example: Convert 41.7 grams of boron to atoms of

Borona) 41.7 g B = __________ mole B

b) 3.86 mol B =_________ atoms B

1 mole B 10.81 g Bx 3.86

6.02 x 1023 atoms B

1 mole B x 2.32x 1024

2. Do all the conversions in the same equationExample: Convert 41.7 grams of boron to atoms of

Borona) 41.7 g B

=_________ atoms B

Converting Grams to Moles to Particles

1 mole B 10.81 g B

x x6.02 x 1023 atoms B

1 mole B = # atoms B

41.7 x 6.02x1023

10.81 2.32x 1024

Try This OneHow many atoms are in 2.13 grams of Helium

INSERT ACTIVE- INSPIRE HERE

Vitamin Lab Activity

You need to get your partner assignmentsYou need to get a lab sheet for your groups and

get the material on the lab sheet.Get to work

Tuesday

Continue lab activity and turn in at the end of the period.

Panther DrillCreate a simple flow

chart that shows the process of converting mass to moles, to atoms of an element. For each step, make sure to show the conversion fractions you would use to do that step Examples of flow chart

outline

Continue w/ Vitamin lab activity

Micrograms to grams

2mcg Mg x 1 gram1,000,000 mcg

Wednesday

P-drillFinish Vitamin Lab and turn in at end of the

period.Students finishing early will do extra credit

assignment converting grams to moles.Exit ticket thumbs up down on grams-moles-

particle converting of an element

Panther Drill (Review Material) 1. Which of the following elements has three valence

electrons?a) lithiumb) boronc) nitrogend) more than one of the above

2. Which of the following is not an acid?a) HNO3

b) CH3COOHc) H2SO4

d) All of these are acids

Thursday

Panther Drill

Find the mass of 1 mole of the following:

Carbon:

Phosphorus:

Iron:

Oxygen Gas:

12.01

30.97

55.85

From the periodic table we get 16.00Amu, but Oxygen is diatomic so in the Real word it would be 16 x 2 = 32.00

Formula Weight or MassFormula Weight is the total of all the atomic masses

for each element in the formula for a compound.

Formula mass, Molar mass, and Formula Weight are the same thing.

The formula mass or weight is like the atomic mass of a compound.

The mass of 1 mole of a compound = the formula mass or weight

ExampleDetermine the formula mass of 1 mole of Magnesium

Chloride?1. Write the chemical formula. (if it is not given)

Remember to “criss-cross” the charges to get the subscripts. (**Signs Drop off)

Magnesium Chloride Mg2+ Cl-1

2. Determine the atomic mass for each element.Mg= 24.31 g/mol ; Cl=35.45 g/mol

3. Look to see how many of each element there are in the formula.

MgCl2

Mg = 1 atom ; Cl = 2 atoms

=

Example (cont)

4. Multiply the number of atoms of each element in the formula by the atomic mass of each element.(Mg) 1 x 24.31 g = 24.31 g(Cl) 2 x 35.45 g = 70.90 g

5. Add up the results: 24.31 g + 70.90 g = 95.21 g

1 mole of MgCl2 = 95.21 g

The formula mass of MgCl2 = 95.21 g

70

A. 1 mole of K2O = ______g

B. 1 mole of antacid Al(OH)3 = ______g

Learning Check How many grams in 1 mole

71

A. 1 mole of K2O

K: 2 x 39.1g/mol =

O: 1 x 16g/mol =

B. 1 mole of antacid Al(OH)3

Al: 1 x 27.0 g/mole = O: 3x 16.0 g/mole =

H: 3 x 1.01 g/mole =

Solution

78.2g =94.2 g K2O

= 78.02 g Al(OH)3

48

16 g 78.2 + 16

3.03

27

27 + 48 + 3.03

Practice

Partner A:Molar mass of Na3P

Molar Mass of CH4O3S (Methanesulfonic acid)

Partner BMolar mass of AlCl3

Molar Mass of C6H12O6

Calculate Molar Mass

Complete the 5 problems on the 1/2 page WS and turn them in in the basket. You need to work by your self and you have 10 to 15 min to complete.

Write the Formula Mass for the following and Turn in when completed

1. NaF2. KGa3. Diphosphorus trioxide4. LiS2

5. Diphosphorus hexachlorine6. Al2O3

Write the Formula Mass for the following and Turn in when completed

1. NaF2. KGa3. Diphosphorus trioxide4. LiS2

5. Diphosphorus hexachlorine6. Al2O3

76

Prozac, C17H18F3NO, is a widely used antidepressant

that inhibits the uptake of serotonin by the brain. It has a molar mass of

1) 40.0 g/mole

2) 262 g/mole

3) 309 g/mole

EXIT TICKET

FridayStudents will learn to convert between grams

and moles of compoundsStudents will work on a comprehensive work

sheet that covers formula mass and converting from formula mass of a compound to moles of a compound.

Individual work will take all period

79

Prozac, C17H18F3NO, is a widely used antidepressant

that inhibits the uptake of serotonin by the brain. It has a molar mass of___________________?

Panther Drill

80

Prozac, C17H18F3NO, is a widely used antidepressant that

inhibits the uptake of serotonin by the brain. It has a molar mass of

17C x (12.01)=

18H (1.01) =

3F (19.0) =

1N (14.01) =

+ 1 O (16.0) =

Solution

309 .36 g/mole of Prozac

204.1718.18 57.0014.01

16.00

309 .36

Converting between Moles and Mass of a compound.

Done the same way as w/ elementsSame conversion Fractions but w/ compounds not

elements and molar mass instead of atomic mass

Grams x 1 mole of compound = # moles compound molar mass of compound

1) See what the problem gives you and see what it is asking for.

2) Determine the chemical formula & calculate the molar mass

3) Do the mathMass to moles: Molar mass on the bottom of the fraction and divide.Moles to mass: molar mass on top and

multiply

REMEMBER WHEN GOING MASS-MOLES WE

DON’T NEED 6.02 X 1023

Converting between Moles and Mass and moles to mass of a compound.

EXAMPLE Mass to MolesHow many moles are in 198 grams of water?

Step 1: See what you are given in the problem and what it wants you to answer.

198 grams H2O ; Wants Moles of H2OStep 2: Determine the chemical formula & calculate

the molar mass H: 2 x 1.08 O: 1 x 16.0

Molar Mass = 18.16 g/mole of water

Converting between Moles and Mass of a compound.

2.16 + 16

Converting between Moles and Mass of a compound

3. Multiply the mass you are given by 1 mole over the molar mass of water. Then simplify, the fraction that is left (divide the top number by the bottom. 198 g divided by 18.16 g = moles water)198 g of water x =

= _______ mole Water

1 mole water 18.16 g water

10.93

198 = 18.16

You Try

How many moles are in the 171.16 grams of Lithium Chloride?

EXAMPLE Moles to MassWhat is the mass of 4.5 moles of CO2

Step 1: See what you are given in the problem and determine the chemical formula of the compound.

Step 2: Calculate the molar massC x 1 = 1x 12.01 gO x 2 = 2 x 16 g

Molar Mass = 44.01 g/mole of CO2

Converting between Moles and Mass of a compound.

12.01 + 16

CO2

Moles to Mass (cont)EXAMPLE Moles to Mass

Step 3: Set up the equation by multiplying the # of moles given by the molar mass over 1 mole.

4.5 moles CO2 x

= 198.05 mol CO2

44.01 gramsCO2

1 mole CO2

= 4.5 x 44.01

Partner A / BPartner A:

You are given 5.46 moles of MgO how many grams do you have?

Partner B:You need to convert 164.4 grams of CaCl2 to moles.

When you are finished explain to each other how you got your answers and sign off on each others

work

Fri

Panther DrillOrganize your materials for your open notes quiz.Ask any questions you have.StudyIf the class is loud we will immediately start the quiz.After you turn your quiz in to me at the desk, pick up

a practicing percentages problem set.

Turn in panther drill from Tuesday, and any other work still out in the basket on the table.

Weds

Mon and Tues = Sub

Panther Drill % review

1. Mary has a monthly salary of $1200. She spends $280 per month on food. What percent of her monthly salary does she spend on food?

280/1200 x 100 = 23.33%

2. What is 98.3% of 23?

98.3%/100 .983 x 23 = 22.61

No Panther Drill for MondayWEDS CLASS WILL MEET IN MEDIA CENTER

Thursday

Percent Practice

Convert the following to fractions:1. 37%

2. .983

98.3/100

37100

Panther Drill

Definition• Percent can be defined as “of one hundred.”

100of

Percents Have Equivalents in Decimals and Fractions

20% .20 20100

15= = =

Decimal FractionFractionSimplifiedPercent

Always simplify fraction to lowest terms!!!

Remember These Equivalent Fractions

12143413

=

=

=

=

50%

25%

75%

33.3%

=

=

=

=

66.6%

20%

40%

60%

23152535

How to Find the Percent of a Whole Number

• The first thing to remember is “of” means multiply in mathematics.

of = x

Copyright © 2000 by Monica Yuskaitis

How to Find the Percent of a Whole Number

• Step 1 - When you see a percent problem you know when you read “of” in the problem you multiply.

25% of 200x

Copyright © 2000 by Monica Yuskaitis

How to Find the Percent of a Whole Number

• Step 2 – Change your percent to a decimal and then move it two places to the left.

25% x 200..

How to Find the Percent of a Whole Number

• Step 3 – Multiply just like a regular decimal multiplication problem.

200x .2550.00

Is/of = %/100

IS = % OF 100

IS x 100 = OF x %

Cross Multiple

Solve for what ever is unknown

Is/of (cont)26 is what % of 34?Step 1) See what you are

givenis = 26of = 34% = ????

Step 2: Set up: is/of = %/10026 = X34 100

Step 3: Isolate unknown and solve:Cross multiply: 34X = 2600Divide to isolate unknown 34X = 2600 34

X = 76.47

Quick Practice A/B Partner

Convert these to fractions:

1) 79%2) .553) 33.3%

Convert these to decimals:

1) 21% 2) 6/83) 66%

.21.75.66

79/10055/100 or 11/20

33/100Or 1/3

Quick Practice 2

Convert these to %:

1) 2/52) 2/103) .59344) .0265) 1.64

40%20%59.34%

2.6%164%

Practice.

Panther Drill Example 1. Homer has a box of assorted doughnuts.

3 of these doughnuts are chocolate. What percentage of Homer's doughnuts are chocolate? (note, we are talking about total number, not mass, in this case.)

Solution

number of chocolate doughnuts% of doughnuts that are chocolate = ------------- x 100 Total # doughnuts

3 % of doughnuts that are chocolate = ----------- x 100 12

.25 x 100 = 25% Chocolate

Percent composition

As we briefly discussed in the beginning of the year, percent composition is the amount of each element in (in %) a compound. Also called mass percent of a compound.

Mass % = mass of element in 1 mole of a compound X 100molar mass of compound

Mass % of H and O in WaterWhat is the % composition of Oxygen in water?Molar Mass H2O: 18.02 g

Mass of O in H2O: 16 g

Mass% O = (16 / 18.02) X 100Mass % O = 0.8879 X 100Mass % O = 88.79 Oxygen accounts for 88.79% of the mass of a

molecule of water

Mass % of H and O in WaterWhat is the % composition of Hydrogen in water?Molar Mass H2O: 18.02 g

Mass of H in H2O: [2 x 1.01] = 2.02 g

Mass% O = (2.02/ 18.02) X 100Mass % O = 0.1121 X 100Mass % O = 11.21 % Hydrogen accounts for 11.21% of the mass of a

molecule of water

Lets do a problem togetherWhat is the mass % of sodium in NaCl?

Partner A /BPartner A: Determine the mass % of Carbon and

Hydrogen in CH4.

Partner B: Determine the mass % of Phosphorus and Oxygen in PO3

Sign off on and check your partners work

Panther DrillDo this somewhere in your notes, I will be around to

check it.

What is the Mass% of each element in Sucrose:

C12H22O11

Panther Drill1. How does ionization energy and atomic radius

change as move to the right across and down the periodic table.

IE: As you move across a period, first ionization energy increases

As you move down a group, first ionization energy decreases.

AR: As you move down a group, atomic radius increases.

As you move left to right across a period, atomic radius decreases.

Work on Lab report

DUE WEDNESDAY at the beginning of class

Choices

• If you finish early, either work on the Chapter 11, pre-assignment OR use your knowledge of elements and the periodic table to complete the “Its Elementary” Chemistry March Madness assignment.

Real Bracket

Its Elementary Bracket RulesRound #

1. The element discovered first wins the game and moves on.

2. Ionization E the highest wins the game and moves on.

3. Element in the group w/ the highest group number wins and moves on.

4. Atomic Radius the highest wins the game and moves on.

Its Elementary Bracket RulesSemi-finals (final 4): Solve the riddles to determine the two

elements that will compete for the championship.

Finals:Fill in the blank on the your insruction

sheet to determine the winner

Chap 11 Pre-Assignment

Use the text book to complete the packet.

Panther Drill 1. List 3 things that you can observe that tell you a

chemical reaction or a chemical change has occurred.

a. New substances are formedb. It burns (light)

c. Temperature changes without adding or removing heat

d. It bubbles (makes a gas)e. It changes colorf. It forms a precipitate

Parts of Chemical

SO3(g) + H2O(l) ---> H2SO4 (aq)

Reactants Products

Yields

State of Compound

State of Compound

Real World ConnectionSO3(g) + H2O(l) ---> H2SO4 (aq)

Above is the equation for acid rainThis results from the release from industry and natural

sources into the atmosphere.The Sulfur trioxide is mixed into the atmosphere when it

rain the Sulfur trioxide mixes with rain water as it condensates from the atmosphere and falls to earth as Sulfuric acid.

Demo Lab1. Was this a chemical rxn? How Could you tell?2. If the word equation is aqueous Hydrochloric acid

and zinc metal mixes to produce Zinc chloride powder, water and Hydrogen gas. What is the symbol equation?

3. Now balance the equation.4. Would there be more H gas produced if I kept

adding HCl until the test tube was 80% full? Why or Why not.

Panther Drill

What “LAWs” tells us that equations must be balanced with = amounts on each side of the yield sign? Be specific.

Law of Conservation of Mass (Mass doesn't change)

Law of Conservation of Matter (Moles don’t change)

STOICHIOMETRY

What is stoichiometry?

• Stoichiometry is the quantitative study of reactants and products in a chemical reaction.

Panther Drill

In your own words define a ratio, and give an example.

What You Should Expect

• Given : Amount of reactants • Question: how much of products can be

formed.• Example

• 2 A + 2B 3C• Given 20.0 grams of A and sufficient B, how

many grams of C can be produced?

What do you need?

You will need to use i. molar ratios, ii. molar masses, iii. balancing and interpreting equations, andiv. conversions between grams and moles.

Note: This type of problem is often called "mass-mass."

Steps Involved in Solving Mass-Mass Stoichiometry Problems

• Balance the chemical equation correctly• Using the molar mass of the given substance,

convert the mass given to moles. • Construct a molar proportion (two molar

ratios set equal to each other) • Using the molar mass of the unknown

substance, convert the moles just calculated to mass.

Mole Ratios

A mole ratio converts moles of one compound in a balanced chemical equation into moles of another compound.

Example

Reaction between magnesium and oxygen to form magnesium oxide. ( fireworks)

2 Mg(s) + O2(g) 2 MgO(s) Mole Ratios:

2 : 1 : 2

Practice Problems

1) N2 + 3 H2 ---> 2 NH3

Write the mole ratios for N2 to H2 and NH3 to H2.

2) A can of butane lighter fluid contains 1.20 moles of butane (C4H10). Calculate the number of moles of carbon dioxide given off when this butane is burned.

Panther Drill What is the ratio between male and female

students in the picture: write all possible ratios, then write it out like a chemical equation.

class picture

Panther Drill answers

1) 17 total students, 7 females, 10 males.Males to females = 10 to 7 or 10 males

7 femaleFemales to males: 7 to 10 or 7 females

10 males Males to total: 10 : 17 10 males/17 studentsFemales to total 7 : 17 , 7 females/17studentsBal Equat: 10 males + 7 females Class

Ratios Ratios can be expressed in many ways: 3:5, 3 to 5 or 3/5We are going to be mainly concerned with ratios

displayed as fractionsThe ratio of A to B = A .

B**** The first item (number) always is the

numerator, the last is the denominator. ***

Ratios1) It takes 2 eggs ¼ onion, 12 slices of jalapenos and 1

slice of cheese to make Mr P.’s favorite omelet what are the total ratio and the ratio of each ingredient to the end(fraction form) result.

Total: 2eggs : ¼onion: 12jalapeno: 1slice: 1omelet2 eggs/1omelet ¼ onion/1 omelet12 slices jalapeno/ 1 omelet1 slice of cheese/ 1 omelet.Is this a problem a good example to use in

chemistry? Why?

Example

Panther Drill

Balance the equation and write down the ratios of each reactant to the product

_____H2 + _____O2 _____H2O

2 mol H2 : 2 mole H2O -- 1:1

1 mol O2 : 2 mole H2O

2 1 2

Panther Drill

Balance the equations and write the mole ratios of each reactant to each product (Should be 4 ratios total)

_____NH3 + _____O2 _____NO + _____H2O

NH3 /NO

NH3 / H2O

O2 /NO

O2 / H2O

Set this chart up in notebookSteps Problem 1 Problem 21

2

3

4

5

Solving Mole-Mass or Mass to Mass Problems. List these in your table next to the number

1. Identify what is given and what the problem is asking for.

2. Write and balance the chemical equation correctly. (depending on what is required)

** 1 and 2 can be in either order3. Using the molar mass of the given substance,

convert the mass given to moles (if needed)4. Construct a molar proportion equation (w/ one

or more molar ratios in conversion fraction form) 5. Convert the moles just calculated to mass

wanted by the problem.

ProblemIf you have 13 moles of oxygen and excess Aluminum,

how many grams Aluminum Oxide will be formed?

1) GIVEN:_____________

NEEDED:______________

13 mol O2

Grams Al2O3

2) Write and or balance the chemical equation correctly.

______Al + _____O2 _____ Al2O3 4 3 2

3) Using the molar mass of the given substance, convert the mass given to moles (if needed)

NOT NEEDED IN THIS PROBLEM BECAUSE YOU HAVE BEEN GIVEN MOLES, OFTEN YOU WILL

BE GIVEN MASS OF A SUBSTANCE!!!!

4) Construct a molar ratio equation (w/ one or more molar ratios in conversion fraction form) & do the math

Mole ratio = 3 moles O2 : 2 moles of Al2O3

Keeping in mind we have oxygen and need to find Al2O3 , what goes in the numerator and what goes in the denominator?

2 moles of Al2O3

3 moles of O2

13 moles of O2 X 2 moles of Al2O3

3 moles of O2

= 8.67mol Al2O3

5) Convert the moles just calculated to mass wanted by the problem (using molar mass)

Atomic masses:

Compound: Al2O3

Molar Mass = (27 x 2) + (16 x 3) =

X =

102 g per mole of Al2O3

O = 16, Al = 27

8.67mol Al2O3 102 g Al2O3

1 mole Al2O3

884.34 g Al2O3

Create a table in your notes like is on the next slide

Set this chart up in notebookSteps Problem 1 Problem 21

2

3

4

5

Solving Mole-Mass or Mass to Mass Problems. List these in your table next to the number

1. Identify what is given and what the problem is asking for.

Have: “have, will react, are consumed…”Need: “are produced, will be made, yields…”

2. Write and balance the chemical equation correctly. (depending on what is required)

Solving Mole-Mass or Mass to Mass Problems. List these in your table next to the number

3. Using the molar mass of the given substance, convert the mass given to moles (needed if you are given grams, not needed if given moles)

4. Construct a molar proportion equation (w/ one or more molar ratios in conversion fraction form)

3 mol N2 / 1 mole Mg

5. Convert the moles just calculated to mass wanted by the problem.

ProblemIf you have 13 moles of oxygen and excess Aluminum,

how many grams Aluminum Oxide will be formed?

1) GIVEN:_____________

NEEDED:______________

13 mol O2

Grams Al2O3

2) Write and or balance the chemical equation correctly.

______Al + _____O2 _____ Al2O3 4 3 2

3) Using the molar mass of the given substance, convert the mass given to moles (if needed)

NOT NEEDED IN THIS PROBLEM BECAUSE YOU HAVE BEEN GIVEN MOLES, OFTEN YOU WILL

BE GIVEN MASS OF A SUBSTANCE!!!!

4) Construct a molar ratio equation (w/ one or more molar ratios in conversion fraction form)

Mole ratio = 3 moles O2 : 2 moles of Al2O3

Keeping in mind we have oxygen and need to find Al2O3 , what goes in the numerator and what goes in the denominator?

2 moles of Al2O3

3 moles of O2

13 moles of O2 X 2 moles of Al2O3

3 moles of O2

= 8.67mol Al2O3

5) Convert the moles just calculated to mass wanted by the problem (using molar mass)

Atomic masses:

Compound: Al2O3

Molar Mass = (27 x 2) + (16 x 3) =

X =

102 g per mole of Al2O3

O = 16, Al = 27

8.67mol Al2O3 102 g Al2O3

1 mole Al2O3

884.34 g Al2O3

Column #2 Mole-Mass Problem You Try

• Problem : 1.50 mol of KClO3 decomposes. How many grams of O2 will be produced?

[k = 39, Cl = 35.5, O = 16]

2 KClO3 2 KCl + 3 O2

Steps…Get Your Correct Answer

• Is equation balanced?• What do you have, what do you need

• Use mole ratio • Get the answer in moles • Convert to grams using molar mass

REMEMBERIf you are given a mass in the

problem, you will need to convert this to moles first. Ok?

YES

1.50 mol of KClO3 grams of O2

3 mol O2 / 2 mol KClO3

O2 = 32

Mass reactant to Mass ProductsGiven the reaction __Mg3N2 + __H2O ___MgO + ___ NH3

If 125 grams of MgO is produced, how much Mg3N2 was required in the reactants. Assume you have plenty (excess) water.

What are the words that tell you what you have and what you need?

Panther Drill

Complete the handout on your desk, it is eerily similar to the one we did last Thursday/Friday!!!

A/B Partners

1. Get w/ a partner, If there is an odd # I will be a partner.

2. 1 Person do problem A, 1 Person do problem B. BY YOURSELVES!!!!!

3. When both are FINISHED. Each partner will explain their problem to the other STEP BY STEP.

4. Sign off on each others work and let me see it.

Partner A and B

For the reaction 2Na + Cl2 2NaCl, how many grams of sodium chloride can be produced from 500. g each of sodium?

For the reaction 2Na + Cl2 2NaCl, how many grams of sodium chloride can be produced from 500. g each of chlorine?

Partner A and B

For the reaction 2Na + Cl2 2NaCl, how many grams of sodium chloride can be produced from 500. g each of sodium?

For the reaction 2Na + Cl2 2NaCl, how many grams of sodium chloride can be produced from 500. g each of chlorine?

Using the unbalanced equation: __CaC2 + __H2O __C2H2 + __Ca(OH) 2.

If 15 grams of C2H2 are produced, how much water will be needed in the reactants?

1) ____ Na3PO4 + ____ KOH ____ NaOH + ____ K3PO4___________________

2) ____ MgF2 + ____ Li2CO3 ____ MgCO3 + ____ LiF___________________

3) ____ P4 + ____ O2 ____ P2O3_________________

4) ____ RbNO3 + ____ BeF2 ____ Be(NO3)2 + ____ RbF_________________

5) ____ AgNO3 + ____ Cu ____ Cu(NO3)2 + ____ Ag_________________

6) ____ CF4 + ____ Br2 ____ CBr4 + ____ F2_________________

7) ____ HCN + ____ CuSO4 ____ H2SO4 + ____ Cu(CN

Panther Drill Chem 4-14

Balance these equations____C6H12O6 + ____O2 ___CO2 + ____H2O

1 6 6 6 ___ GaBr3 + ___ Na2SO3 ___ Ga2(SO3)3 + ___ NaBr

2 3 1 6

Panther Drill 4/15What is the % of Sodium in salt?

Mass % = mass of element in 1 mole of a compound X 100molar mass of compound

% = atomic mass of sodium X 100 molar mass salt = 23 g X 100 =

58.5 g39.32 %

PracticeDetermine the % composition of the following:1. % Cl in NaCl

2. % H in C6H12O6

3. % Al in Al2O3

PracticeDetermine the % composition of the following:1. % Cl in NaCl

2. % H in C6H12O6

3. % Al in Al2O3