First we went over a few questions on the 3.1-3.2 reading sheet. Number 9 is confusing. You are expected to be confused… On question number 13, we will be learning how to do these calculations tomorrow.
We started and finished the first day of learning about the mole.
NOTES
Atoms
- Very small
- We work with them in large amounts so we can measure them in the lab
- Atoms are far too tiny to count
Moles
- No, not the animal
- No, not the thing on your face
- 6.02 * 1023
- This number is also known as avogadro's (avocado’s) number
- This is the amount of atoms in a mass
- Just like 2 is a par and 12 is a dozen, 6.02*1023 is a mole
- EXAMPLES:
- A dozen bowling balls is heavier than a dozen ping pong balls
- A mole of Li weighs less than a mole of Rn
- 1 atom of Co weighs 58.93 amu
- 58.93 g of Co is a mole of it
Molar Mass for Elements
- This is the average atomic mass
- The weight of one mole of the element
- EXAMPLES:
- 12.01 g C = 1 mole C
- 30.97 g P = 1 mole P
- 65.39 g Zn = 1 mole Zn
- 22.99 g Na = 1 mole Na
Molar Mass for Molecules
- (mass of element 1 + mass of element 2 + …)
- Find the mass of the WHOLE molecule
- EXAMPLES:
- H2O
- Mass of H = 1.01 g
- Mass of O = 16.00
- Since there are 2 H’s in H2O, when calculating the molar mass you must multiply the molar mass of an individual H by 2
- (2 * 1.01 g H) + (1 * 16.00 g O) = 18.02 g H2O
- 1 mole of H2O = 18.02 g
Size of the Mole
- An enormous number
- 6.02 * 1023
- 602,000,000,000,000,000,000,000
- Just to give you a better idea…
- 1 mole of watermelon would be found inside a melon larger than the size of the moon
- 1 mole of donut holes would cover the earth to a depth of 5 miles
- One mole of pennies would make at least seven stacks that reach the moon
- By the way, if you spent $1,000,000 a day, you would still have 99% of your wealth by the time you die
MOLES ARE REALLY BIG
Atoms are really small
HW: Calculating molar mass worksheet
No comments:
Post a Comment