This is easy – I got this Mrs. White MOLAR MASS 1/9 Find your new seat – match your # Show how you would set up a math equation for the following in your composition book: How many dollars do you have when you have… 28,220 nickels 28,220 pennies 28,220 quarters This is easy – I got this Mrs. White

Explain to your neighbor what you think a mole is in your own words. What is a MOLE? Explain to your neighbor what you think a mole is in your own words.

Molar Mass vs. Formula Mass – what is the difference? The mass of a mole of any substance is called the molar mass of the substance. For example, the molar mass of a monatomic element is numerically equal to the atomic mass of the element, but expressed in grams/mole. The mass in grams of a mole of any substance is called the formula mass of the substance. Examples: Units are important to be attached after every number in chemistry! Ex. Fe is 55.85 g/mole as molar mass but it is 55.85 g for formula mass Element Molar Mass Formula Mass Fe Au

Determine the molar mass for the following: Sodium 5. HCl Chromium 6. Mg3N2 Oxygen 7. Ca(OH)2 Potassium 8. Al(NO3)3

1/10 Convert to mole from grams COPY: Formula mass (g)= 1 mole = 6.02X1023 atoms or molecules = 22.4 L of a gas  1. 2. 3. 4. What changes if you have to solve for the number of atoms or molecules? 5. How would you use this informaiton to find molar mass instead of formula mass? Amount given in your problem & compound Formula mass of compound Solve for how many moles are in it? 286 g Ag 98 g MgNO35H2O 125 g iron (III) oxide

Equivalence values for money are: 1 dollar = 4 quarters = 10 dimes = 20 nickels = 100 pennies Equivalence values in chemistry are: 1 mole = formula mass (g) = 6.02X1023 atoms = 22.4 L for gases only Sometimes atoms is interchanged with the words molecule, or particles. So if you are asked to solve for molecules or particles it is the same process as if it were atoms

General STEPS TO SOLVE grams to mole problems: #g of compound X = ?? Set up what is called “factor label method or dimensional analysis”, basically this is just math ratios using equivalence values to be able to change units You do this by starting with the given amount & it’s unit; add up the formula mass to use as part of the “equivalence ratio” for grams along with the 1 mole

1/9 Molar Mass Competition (you need your composition notebook to write out your work, your periodic table, & a calculator) login on quizizz.com Join using the code _______ Use your first name & last name initial (ex. Penny W.) so I can get your grade.

1/9 &1/10 After you finish quizizz work then Finish the worksheet from yesterday’s class now. Solve for the “Molar Mass” on the sheet as a group. Put all your names in the group on the top margin Show your math work! Check your answers with the back. Under the side with the answers, write out the steps you must go through in order to determine the molar mass of a compound.

1/5 How do we prove that the samples used in this data table were 1 mole of that sample mathematically? Element Sulfur Silicon Zinc Iron Mass of bag with sample 33.6 30.4 66.8 56.6 Mass of empty bag 1.5 Mass of one mole of the sample 32.1 28.8 65.3 55.1

1/11 Convert between grams and moles: Show all math work! How many moles are in 47.8 g of fluorine gas? 2. How many grams are in 2.01 moles of K2O? 3. List the steps you need to think through in order to set up a mole conversion calculation:

Mole Conversions What are you given? What are you looking for? When converting like units are to be diagonal from each other : TO BE CANCELLED OUT Multiply across the top and divide by the bottom

HOW MANY MOLES ARE THERE IN 15.96g OF PHOSPHORUS TRIOXIDE? GRAMS TO MOLE HOW MANY MOLES ARE THERE IN 15.96g OF PHOSPHORUS TRIOXIDE?

HOW MANY GRAMS ARE THERE IN .9 MOLES OF HCl? MOLE to GRAM HOW MANY GRAMS ARE THERE IN .9 MOLES OF HCl?  

Gram ↔ Moles use molar mass or atomic mass Ex. 32.3 g Na = ? mol Na Ex. 0.56 mol Fe = ? g Fe

1/12 (turn in HW worksheet up front at beginning of class –late after the first few minutes of class) Review Mole & Gram conversions: Show your work: 1. How many moles are in 125.45 g of CaO? 2. How many grams are in 4.5 moles of Sodium?

1/12 Other Mole conversions Make the following conversions: SHOW ALL MATH WORK 3. How many atoms are in 2.5 moles of Aluminum nitride? 4. What is the volume of 2.5 moles of N2? 5. How many grams are in 3.25 x 1024 atoms of lead?

1/12 Quizizz.com assignment: Login using the code 788673 For your name use: 8penny,w your period #, first name & last initial

4 Steps you must think through to set up unit conversions: 1) pick out # unit & compound to set up bracket 2) move the unit & compound you start with down to bottom right of bracket 3) put on the top bracket the unit you are asked to solve for 4) Plug in #’s to make the “equivalence ratio”, to make the top & bottom to equal each other Unit asked to solve for & same cpd started with # Given unit cpd # = # unit cpd you started with 1

1/16 1. What all does 1 mole equal? 2. How many moles are in 8.25 x 1023 atoms of aluminum? 3. How many atoms are in 32.55 g of sodium nitride?

Write specific goals on the index card for the following: 1) classes 2) attendance 3) college

1/16 Mixed up Mole Conversions Make the following conversions: SHOW ALL MATH WORK How many grams in 5.5 moles of potassium oxide? 2. How many moles are there in 115 g of dinitrogen dioxide? 3. How many atoms are in 3.25 moles of sodium nitride? 4. What is the volume of 2.5 moles of O2?

1/17 More Mole Conversions. Make the following conversions: SHOW ALL MATH WORK 1. How many molecules are there in 555 g of CO2? 2. What is the volume of 2.5 moles of Ne gas? 3. How many atoms are in 585,225 g of lead?

Add as #7 on your quiz today: 7. How many grams does a C3H8 (propane) gas tank weigh when it is filled with 7500 L of C3H8?

1/17 Do the following calculations – show your work: How many grams are in 8.22 x 1025 molecules of CO2? How many liters are in 8.22 x 1025 molecules of CO2? How many moles are in 8.22 x 1025 molecules of CO2?

1/18 % Composition Use the pack of color paper to discuss in your group how you would determine the % composition of the different colors in the pack. Write your steps down on the paper provided & then solve for the % composition of each color in your package

1/19 Turn in % composition ws on front table Do “Mixed Mole Conversions (1/19)” Quiz on Moodle You need to write out your problems in your composition book to set them up correctly.

% Composition Equation: Individual elements mass (g) X 100 = % Total formula mass of cpd (g) Example: find the % of each element in MgCl2 24.305 g Mg x 100 = 25.53 % Mg 95.211 g MgCl2 70.906 g Cl2 x 100 = 74.47 % Cl

We need your help reiterating and enforcing district and Eagle expectations. All students should enter your classroom with their ID on every period every day – if they don’t have one send them to get one Students can’t wear hats, hoods, toboggans in the building unless it is a spirit day – please ask them to take them off Students should not be using cell phones during class unless for school work (teacher may request phones to be put away to help students focus on learning in our classrooms) Students are not to stand at your door before bell rings No PDA and students shouldn’t be kissing (we agreed that a simple hug was okay but nothing more)

1/22 Empirical Formula What if you are given the % composition of the elements in a compound and now need to figure out what the compound looks like, what do you do? STEPS: 1) take out of % by assuming this is out of a 100 g by just removing the % sign & put on a gram unit to replace the % sign 2) Now that it is in gram solve for how many moles are in each element using the formula mass of the element from the periodic table 3) Compare the mole answers & divide all by the smallest answer to get a whole number & these will be the subscripts used in the chemicals empirical formula of the compound (if you get a .5 then you will need to multiply all by 2 since you must use whole numbers in compounds) Example: What is the chemical formula when there is 88.8% copper; 11.2% oxygen? Copy the steps down in your composition book

What are the empirical formulas for the following % compositions What are the empirical formulas for the following % compositions? Show your work in your composition book: 40% carbon; 6.7% hydrogen; 53.3% oxygen 92.3% carbon; 7.7% hydrogen 70.0% iron; 30.0% oxygen

Show your work. Find the molecular formulas using the % composition: 4) 5.88% hydrogen; 94.12% oxygen 5) 38.7% chlorine; 61.3% fluorine 6) 7.19% phosphorus; 92.81% bromine 7) 30.4% nitrogen; 69.6% oxygen