moles : a counting unit in chemistry what is a mole? why do we use moles? mole calculations
DESCRIPTION
Homework: Mole Calculations (see handwritten paper). Moles : a counting unit in chemistry What is a mole? Why do we use moles? Mole calculations Factor Label Method Isotope Review Worksheets. Size of Atoms: Diameter Some estimates. Atoms including the electron cloud - PowerPoint PPT PresentationTRANSCRIPT
Moles: a counting unit in chemistry What is a mole? Why do we use moles? Mole calculations
Factor Label Method
Isotope Review Worksheets
Homework: Mole Calculations(see handwritten paper)
Size of Atoms: DiameterSome estimates
Atoms including the electron cloud 1 x 10⁻¹⁰ meters
Nucleus 1 x 10⁻¹²m
Proton 1 x 10⁻¹³ m (note: mass: 1.672 x 10⁻²⁴g)
Electron 1 x 10⁻¹⁶m
Atoms are so small: 1 x 10⁻¹⁰ metersQuarks to Quasars, Powers of Ten
Review: Scientific Notation:aka: exponents, power of ten, etc. Positive exponents:
1 x 10⁶ atoms Negative exponents:
1 x 10⁻⁶ atoms Multiplying with exponents:
(1.5 x 10³ atoms) x ( 4.2 x 10⁶ atoms) (3.4 x 10³ atoms) x (2.0 x 10⁻⁶ atoms)
Dividing with exponents: (1.5 x 10³ atoms) / ( 4.2 x 10⁶ atoms) (3.4 x 10³ atoms) / (2.0 x 10⁻⁶ atoms)
More information: Appendix near the back of the textbook
Moles
Counting Unit in Chemistry
Alternative names for numbers
Gross of pencils
The Mole and Avogadro’s Number What is a mole in chemistry?
How much is a mole? - - -
Why are moles used?
Moles Why are moles used?
How are they measured? (Standards) The amount of substance that contains as
many particles as there are in exactly 12 grams of C-12.
The amount of substance that contains Avogadro’s number of particles.
Molar mass – using the Periodic Table
Salt particle- NaClModel of NaCl as an ionic compound Each salt particle in this photomicrograph
would require the model to be multiplied by 10⁶ or more
Formula Unit: NaClRepresents the repeating units that make up an ionic compound Such as NaCl, CaCl, Al₂O₃
New Term
Amounts: How can we determine the amount of salt particles in this picture?
Mole Flow Chart
Mole
Mole Conversions (Factor Label Method) Moles ↔ Grams
3.5 moles of He = ? Grams
40 grams of He = ? Moles
Molar mass: 1 mole of He = ? Grams
Mole Conversions Moles ↔ Particles (atoms, molecules, compounds, etc.)
3.5 moles of He = ? Atoms
12.04 x 10²³ atoms of He = ? Moles
1 mole = atoms
Review scientific notation
Mole Conversions Moles ↔ Volume of Gas (at STP)
3.5 moles of He = ? Liters
100 Liters of He = ? Moles
1 mole of a gas = Liters
Practice problems: Moles and Mass What is the mass of 0.5 moles of S?
How many grams is equivalent to 0.137 moles of Fe?
4.63 mol P = ? grams P
Practice problems How many moles are in 84.3 grams of Si?
50 grams of Ne = ? moles of Ne
Mole and Atom Conversions How many atoms of Al are in 2.5 moles?
How many atoms of Ag are in 0.26 moles?
How many atoms of He are in 0.0023 moles?
Mole and Atom Conversion How many moles of P contains 1.0 x 10²³
atoms?
How many moles of Au are in 2.8 x 10²º atoms?
Moles, Moles, Moles Lab
Sample in a jar
Mass Moles Atoms
1 mole = ? grams 1 mole = ? atoms
A Mole is a Number
Review
Carbon has 6 protons