Miss Fogg Spring 2016
A particle can refer to an individual atom OR a type of molecule ◦ Jellybean ◦ Baseball ◦ Carbon atoms ◦ Hydrogen atoms ◦ Water molecules ◦ Carbon dioxide molecules Whatever the case, we often need to know the mass of an individual particle in the context of the problem to use the mole concept
What is the mass of 1 mole of carbon? Molar mass tells you mass per mole of substance g1 mol C = 12.01g
What is the mass of 2.00 moles of magnesium? Molar mass tells you mass per mole of substance g2.00 mol C 1 mol C = 48.6g (2)(24.305) = 48.61g
Calculate the formula mass of carbon dioxide, CO g + 2(16.00 g) = g One mole of CO 2 (6.02 x molecules) has a mass of grams
What is the mass of 2.00 moles of water? Molar mass H 2 O = 2(1.01) + (16.00) = 18.02g/mol H 2 O g H 2 O2.00 mol H 2 O 1 mol H 2 O = 36.0g (2.00)(18.02) = 36.04g
Using Avogadro’s Number How many atoms are in 5.5 moles of atoms? 5.5 x (6.02 x )= On your calculator… 5.5*(6.02E23)= 3.311E x = 3.3 x atoms
5.5 mol = atoms 6.02 x atoms 3.3 x mol (5.5)(6.022 x ) How many atoms are in 5.5 moles of atoms?
4.6x10 24 atoms S = moles Sulfur 1 mol S x10 23 atoms S (4.6x10 24 )/(6.022 x ) If we have 4.6x10 24 sulfur atoms, how many moles do we have?
18.2 g Li = atoms Li 1 mol Li 6.02 x atoms Li 1.58 x g Li1 mol Li (18.2)(6.022 x )/6.94 How many lithium atoms are in 18.2g of lithium?
How many grams of lithium are in 3.50 moles of lithium? 3.50 mol Li = g Li 1 mol Li 6.94 g Li 24.3
How many atoms of lithium are in 3.50 moles of lithium? 3.50 mol = atoms 1 mol 6.02 x atoms 2.07 x 10 24
Equal volumes of all gases at the same temperature and pressure contain the same number of molecules. - Amedeo Avogadro 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 At STP (Standard Temperature and Pressure): 1 mole of a gas occupies 22.4 liters of volume
How many moles of hydrogen are in 100 L of hydrogen at STP? 100 L = mol 22.4 L 1 mol 4.64
How many liters are occupied by 3 moles of oxygen gas at STP? 3 mol = L 1 mol 22.4 L 67.2
Mole Atoms or molecules Atoms or molecules Liters Grams 6.02 x AtomicMassAtomicMass L 22.4 L
Use the chart to convert between particles, moles, and volume