Atoms & Molecules- Oct. 30

On Friday we learned about Atoms & Molecules:



For mono atomic elements
a molecule = an element
Eg. Ne=Ne

Diatomic elements
Molecule, Element
Cl2, Cl

Molecules of compounds
H-O-H


Molecule
2 'H' atoms in 1 molecule
1 'O' atoms in 1 molecule


Example:
Write Ammonium Carbonate ---> (NH4)2 CO3
N: 2
H: 8
O: 3
C: 1

Moles <-----> Molecules
6.02 x 10^23 molec/ 1 mol


Example:
How many molecules are in 0.25 mol of CO2?
0.25 mol x 6.02 x 10^23/ 1 mol = 1.505 x 10^23 molec


Example:
5.1772 x 10^24 molecules of H2O = ? moles
5.1772 x 10^24 molecules 1 mol/6.02 x 10^23 =


Example:
Find the number of 'H' atoms in 4.0 mol of ammonia(NH3)?
moles--->molecules--->H atoms
4.0 mol x 6.02 x 10^23/ 1 mol = 2.41 x 10^24 molecules x 3 = 7.22 x 10^24 'H' atoms