Name:
____/____/_________
WS02 – Science
I.
Name:
The concept of Mole
WS02 – Science
The concept of Mole
Example 2 – How many atoms/molecules are in:
Mass Number
· Definition: sum of the number of protons and neutrons in an atom
· Symbol: A
· A=p+n
II.
____/____/_________
a) 1 mol of Hydrogen atoms =
Relative Atomic Mass
· Definition: indicates the mass of an atom measured by comparison with carbon-12
· Atomic Mass Unit: u
· 1 atomic mass unit (1u) = 1.66 x 10-24 g = mass of the carbon-12
b) 2 mols of Oxygen atoms =
c) 1 mol of Water molecules =
!
III.
Mole
· Definition: represents a quantity of matter
· Quantity: one mole = 12g of Carbon-12
· Symbol: mol
IV.
Molar Mass
· Definition: mass (in g) of one mole of a substance
· Symbol: g/mol
#
· "=
$
Ø
M à molar mass (in g/mol)
Ø
m à mass (in g)
Ø
n à number of moles (in mol)
d) 1.5 mol of Carbon atoms =
Example 3 – Convert the following data into moles:
a) 2.408 x 1024 oxygen atoms =
b) 6.02 x 1025 iodine atoms =
c) 3.01 x 1023 nickel atoms =
V.
Avogadro’s Number
· Definition: number of entities in a mole
· Quantity: 6.02 x 1023
d) 3.8 x 1024 steel balls =
Example 1 – What’s the number of entities?
a)
b)
c)
d)
e)
f)
g)
h)
a dozen of eggs =
a hundred eggs =
a mol of eggs =
a mol of atoms =
a mol of molecules =
a mol of cars =
2 mols of atoms =
3.5 mols of molecules =
e) 9.39 x 1025 candies =
f) 1.57 x 1023 diamonds =
1
2
Name:
____/____/_________
WS02 – Science
Name:
The concept of Mole
Example 4 – Complete the table using your periodic table:
Substance
Carbon (C)
Neon (Ne)
Calcium (Ca)
Relative Atomic Mass (u)
____/____/_________
WS02 – Science
The concept of Mole
Example 7 – Calculate the mass (in g) in:
a) 2 mols of molecular hydrogen (H2) =
Molar Mass (g/mol)
b) 3.5 mols Salt (NaCl) =
Example 5 – Calculate the Molar Mass of the molecules:
c) 1.5 mol of Glucose (C6H12O6) =
a) Molecular Hydrogen (H2) =
d) 3 mols of oxygen atoms (O) =
b) Salt (NaCl) =
Example 8 – Complete the following table by filling in the missing information:
c) Glucose (C6H12O6) =
Substance
a. Sodium (Na)
Molar mass (g/mol) Mass (g)
230
Number of moles (mol)
Example 6 – Calculate the number of moles in:
2.02
a) 72g of molecular nitrogen (N2)
2
b. Water molecule (H2O)
10
b) 200g of aluminum (Al)
c. Molecular hydrogen (H2)
18.2
d. Sodium chloride (NaCl)
175.35
e. Copper sulphate (CuSO4)
450
c) 10g of molecular hydrogen (H2)
d) 0.5kg of iron (Fe)
e) 20g of phosphorus (P)
3
4