Announcements Be respectful – no electronics please! Pre-lecture questions due Tuesdays & Thursdays at 8:00 am Everyone will get full credit for today’s pre-lecture question #1. Lab due Friday in discussion Textbook homework due Friday in discussion What is the purpose of the quicksand video?

Discussion #1 How many cars can we make?

Stoichiometry Calculate amounts of reactants or products given an amount of reactant or product. We need to compare what we are given to the mole ratio that reacts (have vs. need) We need a balanced equation (gives us the ratios). Coefficients give us the amount we need (# moles or # particles).

Clicker #1 If you have 8 moles of aluminum and all the copper(II) chloride you need, how many moles of aluminum chloride can you make? 2Al + 3CuCl2 → 2AlCl3 + 3Cu A) 2 mol B) 4 mol C) 6 mol D) 8 mol E) 12 mol

Clicker #2 If you have 6 moles of copper(II) chloride and all the aluminum you need, how many moles of aluminum chloride and how many moles of copper can you make? 2Al + 3CuCl2 → 2AlCl3 + 3Cu Aluminum chloride Copper a) 6 mol AlCl3 4 mol Cu b) 6 mol Cu c) 4 mol AlCl3 d) e) I have no idea.

Clicker #3 If you have 6 moles of copper(II) chloride and 6 moles aluminum, which reactant runs out first? 2Al + 3CuCl2 → 2AlCl3 + 3Cu A) aluminum B) copper(II) chloride C) both run out at the same time D) more information is needed

Starting with Mass… If you have 54.0 g of aluminum and all the CuCl2 you need, what mass of AlCl3 is produced? 2Al + 3CuCl2 → 2AlCl3 + 3Cu

Halftime Demo HCl(aq) + 2NaHCO3(s)  H2O(l) + 2CO2(g) + NaCl(aq) 300 mL 25.0 g 300 mL 50.0 g

Clicker #4 N2 + 3H2  2NH3 How many moles of nitrogen (N2) are needed to use up 6 moles hydrogen (H2)? A) 1 mole B) 2 moles C) 3 moles D) 4 moles E) 6 moles

Example #1 N2 + 3 H2  2 NH3 168.12 g N2 reacts with 12.096 g H2 What mass of NH3 is produced?

More Examples N2 + 3 H2  2 NH3