Presentation on theme: "Chapter 10: Chemical Quantities The Mole. What is a mole? The SI unit that represents the amount of a substance that contains 6.02 x 10 23 representative."— Presentation transcript:
Chapter 10: Chemical Quantities The Mole
What is a mole? The SI unit that represents the amount of a substance that contains 6.02 x representative particles of that substance. What is Avogadro’s Number? The number of particles contained in one mole of a substance. 6.02 x particles 602,000,000,000,000,000,000,000
What is a Representative Particle? Atom: The smallest particle of an element Molecule: Group of atoms joined together by covalent bonds Formula unit: Lowest ratio of elements in ionic bonds Particle: This word can be used for any of the above words
Atomic or Formula Mass Mass of one single representative particle of a substance Measured in atomic mass units (amu)
How do you find Atomic or Formula Mass? Add up the amu for every part of the substance: Find the amu on the Periodic Table C amu NaCl amu amu = amu H2OH2O (1.01 amu x 2) amu = amu
Molar Mass The mass of one mole of any substance Measured in grams/ mole Same as finding atomic mass, but change amu to grams. C amu = g/mol NaCl amu = g/mol H2OH2O amu = g/mol
Converting # of Particles to # of Moles Formula: # of moles =# of particles x 1 mole 6.02 x particles
Sample Problem: How many moles of NaCl are in 3.01x10 23 formula units of NaCl?
Converting # of Moles to # of Particles Formula: # of particles =# of moles x 6.02 x particles 1 mole
Sample Problem: How many particles are in 3 moles of water?
Converting # of Moles to Mass Formula: Mass (g) =# of moles x Molar mass (g) 1 mole
Sample Problem: What is the mass of 1 mole of LiOH?
Converting Mass to # of Moles Formula: # of moles =Mass (g) x 1 mole Mass (g)
Sample Problem: How many moles of NaCl are in grams of NaCl?
Mole-Volume Relationship Avogadro’s Hypothesis: At standard temperature and pressure (STP) 1 mole of any gas occupies the same volume. STP: 0 o C and 1 atm
At STP, 1 mole or 6.02 x particles, of ANY gas, has a volume of 22.4 L L is called the molar volume of a gas.
Converting # of Moles of gas to Volume Formula: Volume of gas =moles of gas x 22.4 L 1 mole
Sample Problem: What is the volume, in liters, of 0.60 mol of SO 2 gas at STP?
Converting Volume of gas to Moles Formula: Moles of gas =volume of gas x 1 mole 22.4 L
Sample Problem: If you collect 8.00 L of O 2 gas, how many moles have you collected?
Calculating Molar Mass from Density Formula: = 22.4 L 1 mole grams mole grams L Molar mass Density
Sample Problem: What is molar mass of a gas with a density of 2.86 g/L at STP?
Percent Composition of a Substance Percent Composition= Mass of element in the compound x 100 Molar Mass of Compound
Sample Problem Find the % composition of H and O in water