1. Welcome! (11/8) Please have out on your desk:
Notes
Homework WS 1
Lab Books open to Lab 5
Practice: given a sample with 1.21g N, 0.161g H, 0.480g C, and 0.640g O
What is the percent composition of each element?
What is the empirical formula?
C6H24N7O6

2. NEW MC
Great q which includes a LOT of content!

3. WS 1 Check

4. Lab #1 Debrief Empirical Formula Results:
Did time left in the Iodine affect the answer?

5. Sources of error If you got moles of Iodine too HIGH:
If you got moles of Iodine too LOW:

6. More MC Questions
What is the empirical formula of a compound containing 50% by mass of element X (Ar = 20) and 50% by mass of element Y (Ar = 25)?
A. XY
B. X3Y2
C. X4Y5
D. X5Y4
(Ar means “relative atomic mass”) D

7. More MC Questions
On complete combustion, a sample of a hydrocarbon compound produces 1.5 mol of carbon dioxide and 2.0 mol of water. What is the molecular formula of this hydrocarbon?
A. C2H2
B. C2H4
C. C3H4
D. C3H8 D

8. EF from Combustion Analysis
Number 11 from your homework! Tough!

9. More MC Questions B

10. More MC Questions C

11. MF from the EF? How?
From the previous problem, if EF is C4H9 and the Relative molecular mass (Molar Mass) is 171 g/mol, what is the molecular formula?
C12H27

12. Big wonderful IB stoich question
On paper

13. Molarity Pre-Activity
Questions: What is the meaning of “Molarity”? How do we calculate it?
Rest of class time and Homework: Finish activity on computers and practice problems

14. Homework Day 2
Molarity pre-activity (Day 2 HW) Finish – due Monday (next class)
Bring lab book all next week!
MC Test corrections due MONDAY (Nov 13th)
Don’t forget to EXPLAIN your reasoning for each one (or show math work)
Written will be given back Monday to correct
Have a great long weekend!

15. Day 3: Molarity, electrolytes and concentration, hydrate review, Lab 6 part 1
Day 4 (gone): lab 6 part 2, dilutions, solution stoich
Day 5: Gravimetric lab (include stoich plus grav)
Day 6: Quiz and move on to gases?