The Mole

CA Standards Students know the quantity one mole is set by defining one mole of carbon 12 atoms to have a mass of exactly 12 grams. Students know one mole equals 6.02 x 1023 particles (atoms or molecules). Students know how to determine the molar mass of a molecule from its chemical formula and a table of atomic masses and how to convert the mass of a molecular substance to moles, number of particles, or volume of gas at standard temperature and pressure.

The Mole 1 dozen = 12 1 gross = 144 1 ream = 500 1 mole = 6.02 x 1023 There are exactly 12 grams of carbon-12 in one mole of carbon-12.

I didn’t discover it. Its just named after me! Avogadro’s Number 6.02 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! Amadeo Avogadro

Calculating Formula Mass Calculate the formula mass of carbon dioxide, CO2. 12.01 g + 2(16.00 g) = 44.01 g  One mole of CO2 (6.02 x 1023 molecules) has a mass of 44.01 grams

Lets Practice NaCl dinitrogen tetroxide CO2 carbon tetraflouride FeCl2 carbon monoxide N2O2 iron (III) oxide NaC2H3O2 sodium carbonate Mg(NO3)2 magnesium hydroxide

Mole Relationships Liters Mole Grams Atoms or molecules 6.02 x 1023 gas @STP 22.4 L 6.02 x 1023 22. 4 L Mole Mole Relationships Atomic Mass Grams

Calculations with Moles: Converting moles to grams How many grams of carbon dioxide are in 3.50 moles of carbon dioxide? 3.50 mol CO2 44.01 g CO2 = g CO2 154 1 mol CO2

Calculations with Moles: Converting grams to moles How many moles of carbon dioxide in 18.2 grams of carbon dioxide? 18.2 g CO2 1 mol CO2 = mol CO2 .414 44.01 g CO2

Calculations with Moles: Using Avogadro’s Number How many molecules of carbon dioxide are in 3.50 moles of carbon dioxide? 3.50 mol 6.02 x 1023 molec. = molec. 2.11 x 1024 1 mol

Calculations with Moles: Using Avogadro’s Number How many molecules of carbon dioxide are in 18.2 g of carbon dioxide? 18.2 g CO2 6.022 x 1023 molec. CO2 1 mol CO2 44.01 g CO2 1 mol CO2 (18.2)(6.022 x 1023)/44.01 = molec. CO2 2.49 x 1023

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. - Amedeo Avogadro At STP (Standard Temperature and Pressure): 1 mole of a gas occupies 22.4 liters of volume

Calculations with Moles: Using Standard Molar Volume How many moles of hydrogen are in 100 L of hydrogen at STP? 100 L 1 mol = mol 4 22.4 L

Calculations with Moles: Using Standard Molar Volume How many liters are occupied by 3 moles of oxygen gas at STP? 3 mol 22.4 L = L 70 1 mol

Lets Practice Find the moles Find the grams 350 g of H3PO4 3.6 mol 25.7 g of Ra(OH)2 .0988 mol 13.6 g of carbon dioxide at STP .309 mol 12.0 L of N2 at STP .536 mol 3 moles of copper(II) cyanide 300 g 0.2 moles of ammonium phosphate 30 g 3.2 L of oxygen gas at STP 4.6 g 8.6 L of H2 at STP .78 g