The mole is one of the big concepts of Chemistry.
The mole is a counting number, just like
1 dozen = 12 things
1 score = 20 things
1 ream = 500 things
1 mole = 6.022 x 1023 things or
1 mole = 602,200,000,000,000,000,000,000
things
We use moles in Chemistry b/c actually
counting things would take too long.
Ex. Counting a moles worth of pennies at 5
pennies/second.
We use moles in Chemistry b/c actually
counting things would take too long.
Ex. Counting a moles worth of pennies at 5
pennies/second.
WOW! Almost 4 quadrillion years!
6.022 x 1023 = Avogadro’s number.
Avogadro’s number just talks about
numbers of particles like atoms.
Ex. 1 mole C = 6.022 x 1023 atoms of C
However, elements have different masses,
So 1 mole of everything is also going to
have different masses.
Ex. 5 grapes vs. 5 grapefruits
Same # of fruit, but very different masses
The decimal numbers on the Periodic Table tell you
the average atomic mass of an element in amu.
By definition that is also the mass of that element in
grams of one mole of that element.
Ex. 1 atom C = 12.011 amu
1 mole C = 12.011 grams C
1 mol Na = 22.990 g Na
1 mol Cl = 35.453 g Cl
these are known as molar masses
(the mass of one mole)
How do you find the molar mass for a compound?
Add up the molar masses of the individual elements.
Ex. NaCl
Na = 22.990 g
Cl = 35.453 g
22.990 g + 35.453 g = 58.443 g
So 1 mole of NaCl = 58.443 g NaCl
Ex. Beryllium nitrate
For Be(NO3)2 take each atom into consideration.
Be
N
O
_______ g x 1 = _______ g
_______ g x 2 = _______ g
_______ g x 6 = _______ g
= _______ g
Ex. Beryllium nitrate
For Be(NO3)2 take each atom into consideration.
Be
N
O
9.012 g x 1 = 9.012 g
14.007 g x 2 = 28.014 g
15.999 g x 6 = 95.994 g
= 133.020 g
So 1 mole Be(NO3)2 = 133.020 g Be(NO3)2
3rd definition of a mole
(molar is the adjective form of mole)
1 mole of a gas = 22.4 Liters of a gas
(for gases only at STP, standard
temperature and pressure)
1 mol O2 = 22.4 L O2
1 mol CO2 = 22.4 L CO2
1 mole = molar mass (g)
(grams from the Periodic Table)
1 mole = volume (L)
(22.4 L of a gas at STP)
1 mole = # of things (atoms)
(6.022 x 1023 atoms)
Ex. 1) 327.2 g of Carbon = ? moles of Carbon
Ex. 2) How many moles are in 3.295 x 1020
atoms of Copper?
Ex. 3) If you capture 17 moles of Chlorine
gas, Cl2 , how many liters do you have?
Ex. 4) Determine the amount of grams in
2.50 moles of sodium phosphate, Na3PO4.
Happy Mole Day to you!
http://www.youtube.com/watch?v=ReMe348Im2w&list=FLnKhdeJuC7b73gwWnbWEr8g&index=17&feature=plpp_video
Mole is a Unit
http://www.youtube.com/watch?v=PvT51M0ek5c
Tom Lehrer CHEMISTRY element song
http://www.youtube.com/watch?v=DYW50F42ss8&feature=BFa&list=FLnKhdeJuC7b73gwWnbWEr8g
Daniel Radcliffe sings "The Elements“
http://www.youtube.com/watch?v=rSAaiYKF0cs&feature=BFa&list=FLnKhdeJuC7b73gwWnbWEr8g
http://www.youtube.com/watch?v=zUDDiWtFtEM
AP Chem Rap
http://www.youtube.com/watch?v=dGgzB7xiF5U&feature=BFa&list=FLnKhdeJuC7b73gwWnbWEr8g
AVOGADRO'S BACK
http://www.youtube.com/watch?v=ZLO47JPHaF0&feature=BFa&list=FLnKhdeJuC7b73gwWnbWEr8g