Part of this formative will be performed as class, in which we will review how to do each part of the percent composition formula.
Please listen, participate, try your best, be open to making mistakes and learning from them.
H2O
Atomic Masses:
H = 1.008 g/mol
O = 16.00 g/mol
Total Mass of each element:
H = 2 atoms H (1.008) = 2.016 g/mol
O = 1 atom O (16.00) = 16.00 g/mol
Molar Mass of H2O:
2.016 + 16.00 = 18.016 g/mol
To find the total mass of an element in a molecule, what two things do I need (select all that apply)?
Which of the following formula is correct for calculating the total mass of an element in a molecule (select all that apply)?
Mg2SO4
To find the total mass of each element, I must identify two things:
a.) The atomic mass of each element in the molecule.
Mg
S
O
b.) The number of each element in the molecule.
Mg
S
O
Total mass of:
Mg
Include the units (g/mol).
Which of the following formula would you use to calculate the molar mass of a molecule (select all that apply)?
Mg2SO4
Total Mass of Each Element:
Mg = 24.31 g/mol
S = 32.06 g/mol
O = 64.00 g/mol
Molar Mass of Mg2SO4
Include the units (g/mol).
To find the percent composition for each element in Mg2SO4, which formula would I use (select all that apply)?
Below is an incomplete percent composition formula.
a.) In the percent composition formula to the left, define the following:
x =
y =
b.) What mathematical operation would I perform between x and y?
c.) What mathematical operation would I perform between the answer to (x/y) and 100?
Total Mass of Each Element:
Mg = 24.31 g/mol
S = 32.06 g/mol
O = 64.00 g/mol
Molar Mass Mg2SO4: 120.37 g/mol
Determine the percent composition for each element in Mg2SO4. Include the units (%).
Round to nearest hundredth.
Mg =
S =
O =
