1. Announcements
Textbook Assignment due Friday in discussion
Electronic HW (Lon-Capa)
Wednesday 10:00 pm
Pre-Lecture Assignments (Lon-Capa)
Post-Lect 2/Pre-Lect 3 – Tuesday & Thursday 8:00 am
First Lab on Monday, lab write-up 1 due Friday in discussion

2. Atomic model and Charges

3. Memorize for Exam Ammonium NH4+ Sulfate SO42- Hydroxide OH- Sulfite
Nitrate
NO3-
Phosphate
PO43-
Nitrite
NO2-
Phosphite
PO33-

4. Memorize for Exam

5. Check-In What is the molar mass of hydrogen gas (H2)? 1.01 amu
4.04 g/mol
1.01 g/mol
2.02 g/mol

6. Check-In

7. C, H, and O Compounds Sucrose C12H22O11 Aspirin C9H8O4 Vanilla C8H8O3
Substance
Formula
Appearance
Sucrose
C12H22O11
Aspirin
C9H8O4
Vanilla
C8H8O3
Glucose
C6H12O6

8. Allotropes of Carbon

9. Example
What is the percent (by mass) of carbon in sucrose (C12H22O11)?

10. Example
What is the percent mass of oxygen in each?
H2O vs. H2O2

11. Clicker #1
Which compound has a greater percent by mass of oxygen? a) Magnesium oxide b) Sodium oxide

12. Example
A compound containing carbon and hydrogen is burned in oxygen and the products of 5.08 g C and g H are collected. Determine the empirical formula of this compound.

13. Clicker #2
How many of the following could be the molecular formula for this compound?
CH2 C2H4 C4H8 C6H12
0 (none) 1 2 3
4 (all)

14. Clicker #3
The molar mass of this compound is 56.1 g/mol. Which of the following is the molecular formula for this compound?
CH2
C2H4
C4H8
C6H12
none

15. Another Example
You have some “nitrogen oxide” compound and you want to figure out what it is (both the formula and the name). You know it’s 30.4% nitrogen by mass and the molar mass is 92.0 g/mol.
NxOy = formula?
name?

16. Tricky problem
If you have equal masses of each compound (H2SO4, C12H22O11, KClO3), which one has the greatest number of oxygen atoms?