8C - Percent Composition Practice

Front

What is percent composition in chemistry?

Back

Percent composition is the percentage by mass of each element in a compound, calculated by dividing the mass of each element by the total mass of the compound and multiplying by 100.

Front

How do you calculate the percent composition of an element in a compound?

Back

To calculate the percent composition of an element, use the formula: (mass of the element in 1 mole of the compound / molar mass of the compound) x 100.

Front

What is the percent by mass of fluorine in CaF₂?

Back

49%.

Front

What is the percent composition of copper (Cu) in Cu₂S?

Back

%Cu = 79.854%.

Front

What is the percent composition of sulfur (S) in Cu₂S?

Back

%S = 20.145%.

Front

What is the percent composition by mass of sulfur in MgSO₄?

Back

27%.

Front

What is the percent composition by mass of oxygen in MgSO₄?

Back

53%.

Front

Which element in potassium cyanide (KCN) has a percent composition of 60.97%?

Back

Potassium (K).

Front

What is the molar mass of CaF₂?

Back

The molar mass of CaF₂ is approximately 78.08 g/mol.

Front

How do you find the molar mass of a compound?

Back

To find the molar mass of a compound, sum the atomic masses of all the atoms in the compound's formula.