Moles

4,254 views

Published on

The mole concept and associated calculations.
**More good stuff available at:
www.wsautter.com
and
http://www.youtube.com/results?search_query=wnsautter&aq=f

Published in: Education, Technology
2 Comments
1 Like
Statistics
Notes
  • ALSO
    I have written six books
    'Sticks - A Golfer’s Tale' - A hacker’s dream comes true.
    'Fish Farm' - Revenge of the old people.
    'Coach' - A mystery in Old school football town in a rural, bigoted, fifties town.
    'The Three Dollar Phoenix' - A mystery set in Newark, New Jersey in the 1970s.
    'The Divine Comedy MMIX' - A humorous play about Jesus returning.
    'The Blood of Judas' - A horror story of revenge set in Nazi Germany.
    All are available at www.smashwords.com
    I have video trailers for 'Coach', 'Fish Farm' and 'The Blood of Judas' at:
    http://www.youtube.com/watch?v=xXSD5Kz-fDY
    http://www.youtube.com/watch?v=a9PTRb14ldc
    http://www.youtube.com/watch?v=ToPp9k9Oq-o
    http://www.youtube.com/watch?v=3eBhMZbsP-I
    Please take a look. Thanks.
    Walt Sautter - wsautter@optonline.net
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • The periodic table usually gives the relative atomic masses or atomic weights, not the atomic masses. The IUPAC definition of the atomic mass is the mass of *one* atom of an element ... in other words the mass of one atom of one isotope, not a weighted average. Maybe nitpicking but ....
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
No Downloads
Views
Total views
4,254
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
174
Comments
2
Likes
1
Embeds 0
No embeds

No notes for slide

Moles

  1. 1. Moles  Atoms Moles  Grams MOLES Copyright Sautter 2014
  2. 2. 2 What is a mole? •A mole is a name for a number just like the word dozen is a name for a number. •As you know, a dozen means the number 12. •A mole is a number too but a much, much, much bigger number. •A mole is 602,000,000,000,000,000,000,000. In words it is six hundred and two hexillion ! •Why is a mole so big? Because it is used to count atoms and molecules which are very, very, very small, It takes lots of them just to be seen much less work with them. A speck of dusk contains trillions of atoms or more!
  3. 3. 3
  4. 4. 5 Counting Atoms and Molecules •If atoms and molecules are so small and numerous, how can they be counted?? •If atoms and molecules could be seen and all the people on the earth began counting the water molecules in our five teaspoons of water and if everyone counted day and night for his entire life, and if we added all their results together we would still not count them all !! •Counting atoms and molecules is difficult but we have an easy way to count them.
  5. 5. How many marbles are in the jar ? How can we find out without counting them all ?? Suppose that we could weigh a dozen of the marbles and we could also weigh the marbles in the jar ! How would that help ? Let’s pretend that the marbles in the jar weigh 2000 grams and a dozen marbles weigh 25 grams. Can you tell the number of marbles in the jar ?
  6. 6. 7 COUNTING LARGE NUMBERS OF SMALL THINGS •In our marble example, the marbles weighed 2000 grams and one dozen of the marbles weighed 25 grams. •Dividing 2000 grams (all the marbles) by 25 grams (the weight of one dozen) gives 80 dozen marbles. •Multiplying 80 times 12 we get 960 marbles in the jar without actually counting all of the marble ! •In the case of atoms or molecules the same idea can be used. If we know the weight of a number of a certain type of atom or molecule and the weight of the sample that we have we can then determine the number of atoms or molecules in the sample by division and multiplication.
  7. 7. 8 COUNTING LARGE NUMBERS OF SMALL THINGS •In counting atoms and molecules we will not use a dozen as our counted quantity. A dozen atoms would be so small that they could never even be seen with traditional microscopes. •Our counted quantity will be one mole (6.02 x 1023 *) atoms or molecules. Unlike our marble example we will not count out and weigh the reference sample. Luckily, this work has been done for us. •The Periodic Table of the Elements lists the weight (mass) of one mole of every element. We can find the weight of one mole of each element in grams. •* 6.02 x 1023 = 602,000,000,000,000,000,000,000 = 1 mole
  8. 8. 9 MOLES GRAMS •MOLES GRAMS •MULTIPLE BY GRAM MOLECULAR / ATOMIC WEIGHT* •GRAMS MOLES • DIVIDE BY GRAM MOLECULAR / ATOMIC WEIGHT •* weight of one mole from the periodic table How are the number of moles determined from the number of grams ?
  9. 9. 10 MOLES  ATOMS •MOLES ATOMS • multiply by 6.02 x 1023 •MOLES ATOMS • divide by 6.02 x 1023 How are the number of atoms determined from the number of moles ?
  10. 10. 11 Click Here

×