Example for next four problems:

Compound formula: MgCl2

Element: Mg

# of Atoms: 1

Element: Cl

# of Atoms: 2

gram formula weight (g): 95.21

Compound Formula: KNO3

Element: K

# of Atoms:

Element: N

# of Atoms:

Element: O

# of Atoms:

gram formula weight (g):

Element: K

# of Atoms: 1

Element: N

# of Atoms: 1

Element: O

# of Atoms: 3

gram formula weight (g): 101.1

For the compound formula KNO3:

Element: K
# of Atoms: 1

Element: N
# of Atoms: 1

Element: O
# of Atoms: 3

Gram formula weight (g): To calculate the gram formula weight, we need to find the atomic weights of each element and multiply them by the number of atoms in the compound.

The atomic weight of K is 39.10 g/mol.
The atomic weight of N is 14.01 g/mol.
The atomic weight of O is 16.00 g/mol.

Calculating the gram formula weight:
(39.10 g/mol × 1 atom of K) + (14.01 g/mol × 1 atom of N) + (16.00 g/mol × 3 atoms of O) = 39.10 + 14.01 + 48.00 = 101.11 g/mol