Announcements Be respectful – no electronics please! Exam #2: Tuesday, Oct. 30th, 7:00-8:30pm Additional Question and answer times posted on course website Old exams are posted on course website Sign up for conflict exam (5-6:30 pm) in 1026 Chem Annex until noon on Oct 30th Online HW 5 due tomorrow by 10:00pm Stoichiometry Workshop on Thursday Must be present in lecture to get credit!

Clicker #1 Which results in the largest balloon full of carbon dioxide? Combination 1 Combination 2 Same Size NaHCO3 H2SO4 Combination 1 10 mol 5 mol Combination 2

Example #1 Given 3.00 g of NaHCO3, how much 3.00 M H2SO4 do we need (in mL)? NaHCO3(g) + H2SO4(aq)  2H2O(g) + 2CO2(g) + Na2SO4(aq)

Example #2 2NaN3(s)  3N2(g) + 2Na(s) What would be the volume of nitrogen gas produced in an airbag containing 6.63 g of NaN3 at 1.05 atm and 22°C? 2NaN3(s)  3N2(g) + 2Na(s)

Clicker #2 6 mol H2 reacts with 4 mol O2 Limiting Mol Product Leftover Reactant A) H2 4 mol 2 mol O2 B) H2 6 mol 1 mol O2 C) O2 4 mol 2 mol H2 D) O2 8 mol 4 mol H2 E) Neither 10 mol None

Clicker #3 12 mol H2 reacts with 5 mol O2 Limiting Mol Product Leftover Reactant A) H2 6 mol 1 mol O2 B) H2 12 mol 7 mol O2 C) O2 5 mol 7 mol H2 D) O2 10 mol 2 mol H2 E) Neither 12 mol None

Clicker #4 16.128 g H2 reacts with 96.00 g O2 Limiting Mol Product Leftover Reactant A) H2 4 mol 1 mol O2 B) H2 8 mol 1 mol O2 C) O2 1.5 mol 2 mol H2 D) O2 6 mol 2 mol H2 E) Neither 6 mol None

Example #3 2H2 + O2  2H2O 4 moles of hydrogen gas and 4 moles of oxygen gas initially react in a flexible balloon at constant temperature. The balloon does not pop as a result of the reaction. If the initial volume of the balloon is 10.0 L, what is the volume of the balloon after the reaction?

Example #4 2H2 + O2  2H2O 5 moles of hydrogen gas and 1 mole of oxygen gas initially react in a rigid container at constant temperature. If the initial pressure in the container is 2.0 atm, what is the pressure in the container after the reaction?

Example #5 Consider the reaction: (NH4)2CO3(s)  2NH3(g) + CO2(g) + H2O(g) What total volume of gas is produced, measured at 453oC and 1.04 atm, if 52.0 g of ammonium carbonate is heated?