Percent Composition Review

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?

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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 composition by mass of magnesium in MgSO4?

Back

20%.

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

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27%.

Front

What is the formula for calculating the molar mass of a compound?

Back

The molar mass of a compound is calculated by summing the atomic masses of all the atoms in the formula.

Front

What is the percent composition of oxygen in magnesium chlorate?

Back

50.21%.

Front

What is the percent composition of beryllium in beryllium cyanide?

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14.76%.

Front

What is the significance of percent composition in chemistry?

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Percent composition helps in understanding the composition of compounds, stoichiometry in reactions, and is essential for quantitative analysis.

Front

How does percent composition relate to empirical and molecular formulas?

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Percent composition can be used to determine the empirical formula of a compound, which can then be used to find the molecular formula if the molar mass is known.