The Mole abbreviated mol

Uhh… Why do we need this “mole” thing? Well, There are two main reasons 1. Ridiculous math. Ex I have this many atoms in my body: 7,000,000,000,000,000,000,000,000,000 Or we can write this as 11,624 moles of atoms just a little easier to work with.

Uhh… Why do we need this “mole” thing? Reason 2 (the real reason) 2. It is AMAZINGLY useful and will give you real amounts from “dumb”equations. Fake Ex I want to blow out my teacher’s windows (but not the building) using ammonium nitrate explosives. >2NH4NO3  2N2 + 4H2O + O2 Alone.. Pretty useless. How much explosive needed? How much gas will be produced? Using the mole: Answer: to fill the room with 35,000L of gas I need 36.7 kg of ammonium nitrate.

Mole Relationships “Mole Map” WRITE the 3 conversions! Liters of Gas @STP Atoms or molecules 22.4 L 22. 4 L 6.022 x 1023 Mole Relationships “Mole Map” WRITE the 3 conversions! 1 Mole Atomic Mass AMU Grams

The Mole: just another unit for amount or quantity 1 dozen = 12 1 gross = 144 1 ream = 500 1 mole = 6.022 x 1023 NOW we can convert directly from AMU to grams. Ex. There are exactly 12 grams of carbon-12 in one mole of C-12.

Avogadro’s Number 6.022 x 1023 is called “Avogadro’s Number” in honor of the Italian chemist Amadeo Avogadro (1776-1855). I didn’t discover it. Its just named after me! I got rid of the “gram-molecule” unit and made the “mole” unit. Amadeo Avogadro

Calculating Formula (Molar) Mass Calculate the formula mass of carbon dioxide, CO2. We convert from the periodic table directly. Molar Mass WS 12.011 g + 2(15.999 g) = 44.009 g/mol One mole of CO2 (6.02 x 1023 molecules) has a mass of 44.009 grams No More AMU’S YAAAAAAAYYYY!!!!

Mole Relationships “Mole Map” WRITE IT! Liters of Gas @STP Atoms or molecules 22.4 L 22. 4 L 6.022 x 1023 DA WS 1 Mole Mole Relationships “Mole Map” WRITE IT! Atomic Mass AMU Grams

THE DREADED Dimensional Analysis AWESOME! Really just a system to convert units that will let you succeed even if you suck at math. BRING A CALCULATOR!!!!

More Pizza, More Problems You have a pizza party with 24 attendees If you have 8 slices per pie And avg slices eaten are 2.8 How many pies do you need? What are the “conversion factors” or ratios to solve this? Then solve! Enough Food= Pizza Party of Legend!

THE Dimensional Analysis METHOD 1. Write down the 1st MEASUREMENT you’re given 2. Multiply by the appropriate conversion or ratio with same unit. (ft to mi, ml to L) 3. For single conversions, arrange the units that we want to cancel on the bottom while the units we want to keep go on top. 4. FOR MULTIPLE STEP CONVERSIONS MAKE SURE THE UNITS YOU WANT CANCELLED ARE ON THE OPPOSITE SIDE 5. Cancel ALL units to see if it is set up correctly. 6. Finally Multiply then divide left to right using PEMDAS 7. Then round using significant figures

Dimensional Analysis EX1 These both give us a relationship between in. and ft. these are CONVERSION FACTORS We use D.A. to cancel units COPY THE METHOD AND EXAMPLE The next example Converts 2.0 ft to in

Dimensional Analysis EX1 The units cancel out leaving only Giving us an answer of 24 in.

Dimensional Analysis EX2: Single Units Show the correct work for this method! HINT YOU NEED THE CONVERSION RATIO! Convert 48 pounds to ounces.

Dimensional Analysis EX3: Single Units two conversions Show the correct work for this method! HINT YOU NEED THE CONVERSION RATIO! Convert 5 days to seconds.

Dimensional Analysis EX4: Single Units 3 conversions Show the correct work for this method! HINT YOU NEED THE CONVERSION RATIO! (Psst. 1 L = 1.06 q) How many mL/s of water fall if 4.0 quarts/minute is measured

Dimensional Analysis EX5 Double Units Show the correct work for this method! HINT YOU NEED THE CONVERSION RATIO! If a car is traveling 24.2 miles/hour, what is its equivalent speed in feet/second? (for double conversions follow the same rules just do one after the other)

Dimensional Analysis EX5 squared2 or cubed3 units (EX CRED #11/12) Show the correct work for this method! HINT YOU NEED THE CONVERSION RATIO! A solid rock occupies a volume of 97.8 cubic centimeters. What is its equivalent volume in cubic meters? *CAREFUL! If your conversion factor is not squared or cubed, do that first! MAKE YOUR OWN NEW RATIO!!!

Calculations with Moles: Converting moles to grams How many grams of lithium are in 3.50 moles of lithium? 3.50 mol Li x 6.941 g Li = g Li 24.3 1 mol Li

Calculations with Moles: Converting grams to moles How many moles of calcium chloride are in 18.2 grams of CaCl2? Mol WS

Calculations with Moles: moles to atoms How many atoms of lithium are in 2.50 moles of lithium? 2.50 mol 6.02 x 1023 atoms x = atoms 1.50 x 1024 1 mol

Calculations with Moles: atoms to mol How many mol of oxygen are in 7.50 x 1024 molecules of oxygen? 7.50 x 1024 Mol WS

Standard Molar Volume 1 mole of a gas occupies 22.4 liters of volume Equal volumes of all gases at the same temperature and pressure contain the same number of molecules. - Amadeo Avogadro 1 mole of a gas occupies 22.4 liters of volume ONLY At STP (Standard Temperature and Pressure): 0o Celsius and 1 atmosphere

Balloons at low pressure! Why STP? High temp Low temp Less than 22.4L Normal temp = 22.4L MORE than 22.4L High pressure Normal pressure= 22.4L LESS than 22.4L Balloons at low pressure! https://www.youtube.com/watch?v=STvBBP6aNC8 Low pressure MORE than 22.4L

So if you have one mole of a gas it will occupy 22.4L in volume. STP and 22.4 L So if you have one mole of a gas it will occupy 22.4L in volume. We can now use this same conversion factor to figure out: Volume of a gas we based on moles Moles of a gas based on its volume. Grams of a gas based on volume or moles AGAIN NOTE THAT: This holds true for a gas at STP. if not at STP (0 °C (32 °F or 273 Kelvin) 1 atm of Pressure) we must make additional calculations.

Calculations with Moles: Using Standard Molar Volume How many liters are occupied by 3.0 moles of oxygen gas at STP? 3 mol 22.4 L x = L 67.2 1 mol

STP and the ‘Magic’ 22.4 L SAMPLE PROBLEMS 1) How many moles of anti-nerve gas do you need if you have a 30 000. L room fully poisoned and there is a 1/1 neutralization ratio needed? 2) How many liters of deadly CO have leaked out of your science experiment if you have lost 135g of mass?

Calculations with Moles MIXED converting grams to atoms How many atoms of lithium are in 128.2 g of lithium? 128.2 g Li 1 mol Li 6.022 x 1023 atoms Li x x 6.941 g Li 1 mol Li (18.2)(6.022 x 1023)/6.941 = atoms Li 1.112 x 1025

Calculations with Moles: Mixed Using Standard Molar Volume How many molecules of hydrogen are in 100 L of hydrogen at STP? 6.022 X1023 molecules 1 mol 100.0 L x x = mol 22.4 L 1 mol = 2.688x1024 molecules

Calculations with Moles MIXED converting grams to liters How many liters of CO2 are in 500.0 g of CO2 MIXED Mol WS