8C - Percent Composition Practice

Front

What is percent composition?

Back

Percent composition is the percentage by mass of each element in a compound, calculated by dividing the mass of the 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 percent composition, use the formula: (mass of element in 1 mole of compound / molar mass of compound) x 100.

Front

What is the percent by mass of oxygen in MgO?

Back

40%

Front

What is the percent by mass of magnesium in MgO?

Back

60%

Front

Find the percent composition of Cu2S.

Back

%Cu= 79.854, %S= 20.145

Front

Which element in KCN has a percent composition of 60.97%?

Back

K

Front

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

Back

53%

Front

What is the molar mass of MgO?

Back

The molar mass of MgO is approximately 40.31 g/mol.

Front

What is the molar mass of Cu2S?

Back

The molar mass of Cu2S is approximately 159.16 g/mol.

Front

What is the molar mass of KCN?

Back

The molar mass of KCN is approximately 65.12 g/mol.