Mole Calculations; % Comp; MF/EF FLASHCARD

Front

How many molecules are in 1 mole of a substance?

Back

6.022 x 10^23 molecules (Avogadro's number)

Front

What is the formula to calculate the mass of a substance in grams from moles?

Back

Mass (g) = Moles x Molar Mass (g/mol)

Front

Define Molar Mass.

Back

The mass of one mole of a substance, usually expressed in grams per mole (g/mol).

Front

What is the difference between empirical formula and molecular formula?

Back

Empirical formula shows the simplest whole-number ratio of atoms, while molecular formula shows the actual number of atoms 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 water (H2O)?

Back

18.02 g/mol.

Front

If you have 2 moles of sodium chloride (NaCl), how many grams do you have?

Back

2 moles x 58.44 g/mol = 116.88 g.

Front

What is the empirical formula of glucose (C6H12O6)?

Back

CH2O.

Front

How many grams are in 0.5 moles of carbon dioxide (CO2)?

Back

0.5 moles x 44.01 g/mol = 22.01 g.

Front

What is the percent composition of oxygen in aluminum oxide (Al2O3)?

Back

47%.