1. Chemical Quantities III A.K.A. Stoichiometry

2.  stoicheion (element; Greek) + metron (measure; Greek)  Quantitative relationship between reactants and products  Created by Jeremias Benjamin Richter in 1792 What is Stoichiometry?

3.  How much water is produced when 1.5 g of C 6 H 12 O 6 is burned in oxygen?  C 6 H 12 O 6 + O 2  CO 2 + H 2 O; Is it balanced?  C 6 H 12 O 6 + 6 O 2  6 CO 2 + 6 H 2 O How do we calculate the mass of a product if we know the mass of a reactant?

4.  We have 1.5 grams of C 6 H 12 O 6 ; we need a mass-mass conversion pathway Create a Conversion Pathway Step 1 Mass of C 6 H 12 O 6 Moles of C 6 H 12 O 6 Step 2Step 3 Moles of H 2 O Mass of H 2 O

5. Mass of C 6 H 12 O 6 Molar MassMoles of C 6 H 12 O 6 1.5 g C 6 H 12 O 6 1 mol C 6 H 12 O 6 = 0.0083 mol C 6 H 12 O 6 180 g C 6 H 12 O 6 C 6 H 12 O 6 + 6 O 2  6 CO 2 + 6 H 2 O Step 1 Moles of C 6 H 12 O 6 Molar RatioMoles of H 2 O 0.0083 mol C 6 H 12 O 6 6 mol H 2 O 6 = 0.050 mol H 2 O 1 mol C 6 H 12 O 6 Moles of H 2 OMolar MassGrams of H 2 O 0.050 mol H 2 O18 g H 2 O= 0.090 g H 2 O 1 mol H 2 O Step 2 Step 3

6.  How much aluminum oxide is generated with 2.3 g Al reacting with iron (III) oxide  Al + Fe 2 O 3  Fe + Al 2 O 3; is it balanced?  2 Al + Fe 2 O 3  2 Fe + Al 2 O 3 Another Mass-Mass Conversion

7. Mass of AlMolar MassMoles of Al 2.3g Al1 mol Al= 0.085 mol Al 27 g Al 2 Al + Fe 2 O 3  2 Fe + Al 2 O 3 Step 1 Moles of AlMolar RatioMoles of Al 2 O 3 0.085 mol Al1 mol Al 2 O 3 = 0.043 mol Al 2 O 3 2 mol Al Moles of Al 2 O 3 Molar MassMass of Al 2 O 3 0.043 mol Al 2 O 3 102 g Al 2 O 3 = 4.3 g Al 2 O 3 1 mol Al 2 O 3 Step 2 Step 3

8. Mass-Mass Conversions SmartBoard Exercise

9.  Chemical Quantities III Worksheet  Complete the first problem as a team in your row  Complete the second problem as a pair with the person on your right  Complete the next few problems solo It’s your turn to Team, Pair, Solo

10.  Read pp. 251-258  Answer problems pg. 262: 31, 33, 35, 39, 40 Homework