CH12 – Back and Forth

Date

• P4 – Tuesday, February 6th
• P5 – Tuesday, February 6th
• P7 – Tuesday, February 6th

New Idea – Percent Composition (formula to mass)

• Assume 1 mole sample
• Moles –> Mass (each element)
• Total the mass
• Divide each mass by total

New Idea – Empirical Formula (mass to formula)

• Assume 100 gram sample
• percent to grams
• gram to moles
• divide by smoles
• multiply until whole
• <known molar mass>

Examples

• practice

Homework

• Ch. 3 (79, 83, 84)