1. Creating a Positive Learning Environment for Everyone
Be respectful of your classmates
Save conversation for clicker portions of lecture
Put cell phones in “airplane” mode
Turn off tablets
Close laptops

2. Announcements Exam #2: Tuesday, Oct. 31th, 7:00-8:30pm
Review Sessions will be posted soon
Old exams are posted on course website
Sign up for conflict exam (5-6:30 pm) in 1026 Chem Annex
Online HW 5 (Type II) due tomorrow by 7:00pm
Lab This Week: Review Questions for Exam 2 (answers due online by 10/27 at 5:00pm)
Stoichiometry Workshop on Thursday
Must be present in lecture to get credit!

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

4. Clicker #2 12 mol H2 reacts with 5 mol O2
Limiting Mol Product Leftover Reactant
A) H mol 1 mol O2
B) H mol 7 mol O2
C) O mol 7 mol H2
D) O mol 2 mol H2
E) Neither mol None

5. Clicker #3 16.128 g H2 reacts with 96.00 g O2
Limiting Mol Product Leftover Reactant
A) H mol 1 mol O2
B) H mol 1 mol O2
C) O mol 2 mol H2
D) O mol 2 mol H2
E) Neither mol None

6. Example #1 2H2(g) + O2(g)  2H2O(g)
To react 10.0 g of hydrogen gas, what volume of oxygen gas would you need at 1.05 atm and 22°C?
2H2(g) + O2(g)  2H2O(g)

7. Example 1 - Clicker #4 2H2(g) + O2(g)  2H2O(g)
To react 10.0 g of hydrogen gas, what volume of oxygen gas would you need at 1.05 atm and 22°C?
2H2(g) + O2(g)  2H2O(g)
Next Step?
A) Use PV = nRT
B) Find limiting reactant
C) Use mole ratio between H2 and O2

8. Example #2 - Clicker #5
Given 3.00 g of Mg, how much 3.00 M HCl do we need (in mL)?
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
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Does this problem involve finding a limiting reactant?
A) Yes
B) No
C) No idea

9. Example #2 Given 3.00 g of Mg, how much 3.00 M HCl do we need (in mL)?
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

10. Example #3 - Clicker #6
Which case makes the larger balloon (at the same temperature and pressure)?
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Case #1: 10.0 g Mg with 586 mL of 3.00 M HCl
Case #2: 15.0 g Mg with 274 mL of 3.00 M HCl
Does this problem involve finding a limiting reactant?
A) Yes
B) No
C) No idea

11. Example #3
Which case makes the larger balloon (at the same temperature and pressure)?
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Case #1: 10.0 g Mg with 586 mL of 3.00 M HCl
Case #2: 15.0 g Mg with 274 mL of 3.00 M HCl

12. Example #4 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?

13. Example #4 - Clicker #7 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?
__________________________________________________
First step?
Find volume using PV=nRT
Use mole ratio between ammonium and carbon dioxide
Convert mass of ammonium carbonate to moles

14. Example #4 - Clicker #8 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?
__________________________________________________
Next step?
Find moles of water using mole ratio & moles (NH4)2CO3
Find moles of carbon dioxide using mole ratio & moles (NH4)2CO3
Use PV = nRT to find volume of NH3 produced
Use PV = nRT to find volume of ammonium carbonate produced
A - C are possible

15. Example #4 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?