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Wake-up. Study Polyatomic Ions for about 5/10 minutes. Write NO WAKE-UP on Friday. MOLAR MASS. What is molar mass? How do you calculate molar mass?. Mole. The unit for a specific amount of a substance/particle. Avogadro’s Number. 1 mole = 6.02 x 10 23 particles.
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Wake-up • Study Polyatomic Ions for about 5/10 minutes. Write NO WAKE-UP on Friday
MOLAR MASS What is molar mass? How do you calculate molar mass?
Mole The unit for a specific amount of a substance/particle
Avogadro’s Number 1 mole = 6.02 x 1023 particles
Types of particles measured by Moles Atoms, elements, covalent compounds or ionic compounds
Practice Problem 1. How many cadmium atoms are there in 6.57x103 moles?
Practice Problem 2. How many moles of nitrogen are there in 4.3x1023 molecules?
Mole Road Map Moles to Mass OR Molar Mass
Molar Mass The sum of the atomic weights of all the atoms in a molecule
Molar Mass Units Grams Moles Molar Mass (MM) = (g/mol)
Use Periodic Table to determine MM If there was one mole of Sodium (Na),it’s molar mass would be ________________g/mol.
Carbon MM= 12.0 g / mol • Mercury MM= 200.6 g / mol • Iron MM=55.8 g / mol
How many particles do these elements contain? Particles: Atoms Formula Units Molecules
How do you calculate molar mass of compounds? SO3 • EX. Sulfur Trioxide Chemical Formula = ___________ • How many total atoms make up one molecule? • Total Atoms = _____________ • S: ___ x ______ = • O: ___ x ______ = • Molar Mass: __________ + ____________ • The molar mass of sulfur trioxide = _______ g/mol 1 + 3 = 4 1 32.1 32.1 48.0 16.0 3 48.0 32.1 80.1
Your Turn PCl3 • EX. Phosphorus Trichloride Chemical Formula = _________ • How many total atoms make up one molecule? Atoms = _______ • P: ___ x ______ = • Cl: ___ x ______ = _________ + • Sodium Hydrogen Carbonate NaHCO3 1+3=4 1 31.0 31.0 3 35.5 106.5 137.5 grams per 1 mol MM = 84.0 g / mol
Conversions using Molar Mass 1. How many grams are in 4.5 moles of sodium fluoride?
Conversions using Molar Mass 2. How many moles are in 3.4 x 10-7 grams of silicon dioxide?
Conversions using Molar Mass 3. How many moles are in 68 grams of Copper (II) hydroxide?
Conversions using Molar Mass 4. How many grams are in 2.3 x 10-4 moles of Calcium phosphate?