1. Do Now & Announcements
Take out Empirical/Molecular formula Independent Study to be checked.
Work on back page as your do now.
Unit 2A Quest FRI 9/25
Key is posted for review
Will be checked!
Case Study due TUES 9/29 (B), WED 9/30 (A)

2. If when you divide all the # of moles by the smallest # of moles and your mole ratios end in:
Multiply all mole ratios by ____ to get all whole numbers for your mole ratio
~0.5 (1/2)
X 2
~.33 (1/3) ,
~.66 (2/3)
X 3
~0.25 (1/4),
~0.75 (3/4)
X 4

3. 25.94% N 74.06% O. Determine Empirical Formula
25.94 𝑔 𝑁 × 1 𝑚𝑜𝑙𝑒 𝑁 𝑔 𝑁
74.06 𝑔 𝑂 × 1 𝑚𝑜𝑙𝑒 𝑂 𝑔 𝑂
=1.85 mole N
=4.63 mole O
1.85 mole N
What happens when you divide and you don’t get a whole number?
=1 N
1.85 mole
4.63 mole O
=2.5 O
1.85 mole

4. “NO2.5”
We need to multiply the entire thing by a whole number so that we can get whole number subscripts
NO2.5 x 2
= N2O5

5. Chemistry in Forensics on TV/Movies…

6. Mass Spectrometer Analyzes Samples by Mass and % Composition

7. Mass Spectrometer Signal for Neon *you need to analyze the data!

8. Empirical/Molecular Formula Tasks
Get stamped when done