T6 - Recap

Front

What is molar mass?

Back

The molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all atoms in a molecule.

Front

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

Back

Percent composition is calculated by dividing the mass of the element in one mole of the compound by the molar mass of the compound, then multiplying by 100.

Front

What is the empirical formula?

Back

The empirical formula is the simplest whole-number ratio of elements in a compound.

Front

What is the molecular formula?

Back

The molecular formula shows the actual number of atoms of each element in a molecule of a compound.

Front

How do you determine the percent by mass of an element in a compound?

Back

Percent by mass is calculated by dividing the mass of the element by the total mass of the compound and multiplying by 100.

Front

What is the molar mass of NaCl?

Back

The molar mass of NaCl (sodium chloride) is approximately 58.44 g/mol.

Front

What is the percent composition of water (H2O)?

Back

The percent composition of water is approximately 11.19% H and 88.81% O.

Front

How do you find the molecular formula from percent composition?

Back

Convert the percent composition to grams, then to moles, find the simplest ratio of moles, and use that ratio to write the empirical formula. If needed, compare the molar mass to find the molecular formula.

Front

What is the significance of the molar mass in chemical reactions?

Back

Molar mass is used to convert between grams and moles, allowing chemists to calculate the amounts of reactants and products in a chemical reaction.

Front

What is the percent composition of benzene (C6H6)?

Back

C = 92.2%, H = 7.8%.