The MOLE CH 11

Mole (mol) SI base unit used to measure the amount of a substance One (1) mole of anything is 6.02 X 1023 Compare to other counting units: Pair = 2 Dozen = 12 Gross = 144 Ream = 500 Mole = 6.02 X 1023

Math Practice How many gloves are there in 8 prs? How many roses in 2.5 doz? How many atoms in 0.5 mol?

Avogadro’s Number is 6.02 X 1023 Amedeo Avogadro determined the volume of one mol of gas

Molar Mass The mass in grams of one mole of any pure substance Numerically equal to its atomic mass (amu) but, has the units g/mol Example: An atom of manganese has a mass of 54.94 amu A molar mass = 1 mol of manganese 54.94 g of Mn contains 6.02 X 1023 atoms of Mn

Molar Mass Ionic Compounds Use the formula mass Example: Sodium Chloride A mole of sodium has mass = 22.99 g A mole of chloride ions has mass = 35.45 g One mole of NaCl = 58.44 g Or, the molar mass of NaCl is 58.44 g/mol

What is the molar mass of potassium nitrate?

Molar Mass Of a metal Use the atomic mass converted to g/mol Example: Iron A mole of iron has mass = 55.84 g One mole of Fe = 55.84 g Or, the molar mass of iron is 55.84 g/mol

Practice What mass of aluminum foil will contain an Avogadro’s number of Al atoms? An experiment calls for 0.250 mol of Al. How much should be weighed out?

Molar Mass of Nonmetallic Elements Use the mass of 6.02 X 1023 molecules What is the molar mass of: A. hydrogen B. nitrogen C. oxygen

Molar Mass of Molecules What is the molar mass of water? A mol of water molecules contains _____ mol of H atoms _____ mol of O atoms The molar mass of water is ______________

Calculations with Moles a. Counting mol if given the mass Ex. How many moles of calcium are there in a 16.0 g sample? Track Method: =

Calculations with Moles a. Counting mol if given the mass Ex. How many moles of calcium are there in a 16.0 g sample? Track Method: 16.0 g Ca = mol

Calculations with Moles a. Counting mol if given the mass Ex. How many moles of calcium are there in a 16.0 g sample? Track Method: 16.0 g Ca 1 mol Ca 40.1 g Ca = mol

Calculations with Moles a. Counting mol if given the mass Ex. How many moles of calcium are there in a 16.0 g sample? Track Method: 16.0 g Ca 1 mol Ca 40.1 g Ca = 0.399 mol

Calculations with Moles b. Relating mass to number of particles Ex. What is the mass of 2.50 X 1021 calcium atoms? Track Method: 2.50 X 1021 atoms = g Ca

Calculations with Moles b. Relating mass to number of particles Ex. What is the mass of 2.50 X 1021 calcium atoms? Track Method: 2.50 X 1021 atoms 40.1 g Ca 6.02 X 1023 atoms = g Ca

Calculations with Moles b. Relating mass to number of particles Ex. What is the mass of 2.50 X 1021 calcium atoms? Track Method: 2.50 X 1021 atoms 40.1 g Ca 6.02 X 1023 atoms = 0.166 g Ca