CP16 – Formulas and Masses

The world is a magical place

Date

• Monday, February 12th

Class Business

• Questions?
• Collect LNB

Recap Last Class – Percent Composition

• given formulas
• asked for a mass breakdown
• assume 1 mole of the substance
• process
• new example: propane (C3H8)

New Idea – Empirical Formulas

• given mass percent
• determine formula
• empirical vs. true formula
• examples

Empirical Formulas – Process

• assume 100-gram sample
• percent to grams
• gram to moles
• divide by smoles
• multiply ’til whole

Practice

• practicing

Next Class Meeting = Test

• Objectives: Unit 7 & Unit 8 (let’s look now)
• Practice Problems in textbook
• I will post last year’s test as well

Homework

• Study for the test