Conversions (Mass-Mole-Particles) & Percent Comp.

Front

What is the empirical formula?

Back

The empirical formula is the formula of a compound that shows the smallest whole-number mole ratio of the elements in the compound.

Front

What is the difference between empirical formula and molecular formula?

Back

The empirical formula shows the simplest ratio of elements, while the molecular formula shows the actual number of atoms of each element in a molecule.

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 NaOH?

Back

The molar mass of NaOH is 39.997 g/mol.

Front

How many grams are in 238 moles of arsenic?

Back

There are 17,800 g in 238 moles of arsenic.

Front

What is the percent composition of oxygen in copper (II) oxide (CuO)?

Back

The percent composition of oxygen in CuO is 79.89%.

Front

What is the formula to convert moles to grams?

Back

Grams = Moles x Molar Mass.

Front

What is the formula to convert grams to moles?

Back

Moles = Grams / Molar Mass.

Front

What is the significance of the molar mass in conversions?

Back

Molar mass is used to convert between the mass of a substance and the amount in moles.

Front

How do you determine the empirical formula from mass data?

Back

1. Convert grams to moles for each element. 2. Divide by the smallest number of moles. 3. Round to the nearest whole number.