Percent Composition

Front

What is percent composition?

Back

Percent composition is the percentage by mass of each element in a compound.

Front

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

Back

Percent composition = (mass of element in 1 mole of compound / molar mass of compound) x 100%.

Front

What is the molar mass of MgO?

Back

Molar mass of MgO = 24.31 g/mol (Mg) + 16.00 g/mol (O) = 40.31 g/mol.

Front

What is the percent by mass of magnesium in MgO?

Back

Percent by mass of Mg = (24.31 g/mol / 40.31 g/mol) x 100% = 60%.

Front

What is the percent by mass of oxygen in MgO?

Back

Percent by mass of O = (16.00 g/mol / 40.31 g/mol) x 100% = 39.7% (approximately 40%).

Front

What is a cation?

Back

A cation is a positively charged ion formed when an atom loses one or more electrons.

Front

What is an anion?

Back

An anion is a negatively charged ion formed when an atom gains one or more electrons.

Front

What is an ionic bond?

Back

An ionic bond is formed when valence electrons are transferred from one atom to another, resulting in the attraction between oppositely charged ions.

Front

What is the relationship between pressure and volume in gases?

Back

The relationship is inverse; as pressure increases, volume decreases (Boyle's Law).

Front

What is a family in the periodic table?

Back

A family is a column of elements in the periodic table that share similar chemical properties.