AP Chem - Stoichiometry

Unit 5

What is stoichiometry?

calculation involved with quantities in chemical equations/reactions

What is the fundamental unit for counting particles and conversions?

mole

What is Avogadro’s number?

6.02 × 10²³

How many particles are in one mole of a substance?

6.02 × 10²³ particles

What is the mass of a mole called?

• gram formula mass

• molecular weight

• formula weight

• etc.

What are the mole conversions (“triangle”)?

grams ←→ moles ←→ # of particles

What do you use to convert grams ←→moles?

gfm / molar mass

What do you use to convert moles ←→# of particles?

Avogadro’s #

How many liters are in one mole of a gas?

22.4 L

What is the formula for percent composition by mass?

(# of atoms)(gfm) / (gfm of compound) * 100

OR

part / whole * 100