Transcript moles and molar conversions
Today’s Agenda Catalyst Holy Moley!
Molar Conversions Representative Particles Molar Mass Work Time Exit Question
HOMEWORK:
Today’s Objectives SWBAT define the mole, representative particles, and Avogadro’s number.
SWBAT use Avogadro’s number and molar mass to complete molar conversions.
LESSON TITLE: MOLES AND MOLAR CONVERSIONS
What is a mole to us chemists?
A benign overgrowth of cells because of a failure in mitosis?
NO! But gross… A rascly little rodent?
NOOOO!
A TV show featuring celebrities?
NOOOOO! Then WHAT IS IT?????!!!???!?!?!???!!!!
Measuring Matter
Remember! Chemistry is a quantitative science that requires you to measure amounts of matter.
Units to Count Matter Think of the term “ a dozen ”… How many donuts are in a dozen? How many eggs are in a dozen?
Avogadro’s Number Just like a dozen refers to 12 objects … The mole refers to…
6.02 x 10
23 REPRESENTATIVE PARTICLES
602,000,000,000,000,000,000,000
What is a mole to us chemists?
Key Point#1: Chemists use a unit called the mole to measure matter.
1 mole ALWAYS equals…
Molar Mass OR Avogadro’s number
Molar Mass = the grams in 1 mole
Avogadro’s Number = 6.02 x 10 23
Moles – Mass
Key Point #2: Molar mass is used to convert between moles and mass.
Mole – Mass Example Tungsten is a rare metal that is found naturally on Earth only in chemical compounds. If it was isolated, how many grams would be in 3.4 moles of tungsten (W)?
Moles – Particles
Key Point #3: Avogadro's number (6.02 x 10 23 ) is used to convert between moles and representative particles (atoms, formula units, molecules).
It all relates back to the mole… Guess what’s coming back…
More on Representative Particles
Substance Chemical Formula Representative Particle Representative Particles in 1 Mole
Copper Cu Atom 6.02 x 10 23 Atomic Nitrogen N Atom 6.02 x 10 23 N 2 Molecule 6.02 x 10 23 Elemental Nitrogen Water Sucrose Calcium Ion Calcium Fluoride H 2 O C 12 H 22 O 11 Ca 2+ CaF 2 Molecule Molecule Ion Formula Unit 6.02 x 10 23 6.02 x 10 23 6.02 x 10 23 6.02 x 10 23
Mole – Particle Example
Titanium is a strong metal that is corrosion resistant. Because it is biocompatible, it is used in a gamut of medical applications including surgical implants like hip balls and sockets. Titanium is often alloyed with aluminum and vanadium. How many moles are equal to 4.5x10
23 atoms of titanium (Ti)?
TRAIN TRACKS!!!
Step 1: What to what?
Step 2: Write conversion factor(s) Step 3: Train tracks
Scientific Notation on the Calculator Don’t forget! When you need to type in a scientific notation number like 6.02 x 10 23 … Type 6.02 E 23 instead
SAVE TIME AND LOOK COOL!
You try!
Potassium chloride has a crystalline structure like many other ionic salts. How many moles are equal to 3.61x10
24 representative particles of potassium chloride (KCl)?
Info from Avogadro...
1 mol KCl = 6.02x10
23 rep. particles KCl 1 mol KCl = 6.02x10
23 formula units KCl
You try!
Sucrose, C 12 H 22 O 11 , is also known as saccharose. If you have 2.1 moles of sucrose, how many molecules of sucrose do you have?
Info from Avogadro...
1 mol C 12 H 22 O 11 = 6.02x10
23 molecules C 12 H 22 O 11
Molar Mass: Step-Up Problem #2 Write this down!!!
If we have 20 grams CH 4 , how many moles of CH 4 do we have?
Independent Practice Worksheet time!
Show your work!
Turn into folder when done!
Exit Question 1.
2.
What information do we get from Avogadro?
What is the molar mass of Helium?
HW: 1 st Page of Worksheet (front and back)