Formula Mass of Compounds

Molar mass of an element Molar mass = mass in grams of 1 mole of any pure substance. Molar mass of an element numerically equal to atomic mass but units change to grams per mole.

Molar mass of elements Na has an atomic mass of 22.990 amu so its molar mass = 22.990 grams K has an atomic mass of 39.098 amu so its molar mass = 39.098 grams. Ca has an atomic mass of 40.078 amu so its molar mass = 40.078 grams.

Molar mass Also called formula mass. Or gram formula mass.

Molar Mass of Compounds = sum of the masses of the atoms in the formula. Round atomic masses to the nearest tenth. Ex: H2O 2 X H = 2 X 1.0 = 2.0 1 X O = 1 X 16.0 = 16.0 Sum = 2.0 + 16.0 = 18.0

Molar Mass of Compounds Try CH4 1 X C = 1 X 12.0 = 12.0 4 X H = 4 X 1.0 = 4.0 Sum = 4.0 + 12.0 = 16.0

Molar Mass of Compounds Try CO2 1 X C = 1 X 12.0 = 12.0 2 X O = 2 X 16.0 = 32.0 Sum = 12.0 + 32.0 = 44.0

Molar Mass of Compounds Try NaCl 1 X Na = 1 X 23.0 = 23.0 1 X Cl = 1 X 35.5 = 35.5 Sum = 23.0 + 35.5 = 58.5

Molar Mass of Compounds Try C6H12O6 6 X C = 6 X 12.0 = 72.0 12 X H = 12 X 1.0 = 12.0 6 X O = 6 X 16.0 = 96.0 Sum = 72.0 + 12.0 + 96.0 = 180.0

Molar Mass of Compounds Try Cu(OH)2 1 X Cu = 1 X 63.5 = 63.5 2 X O = 2 X 16.0 = 32.0 2 X H = 2 X 1.0 = 2.0 Sum = 63.5 + 32.0 +2.0 = 97.5

Molar Mass of Compounds Try Al(NO3)3 1 X Al = 1 X 27.0 = 27.0 3 X N = 3 X 14.0 = 42.0 9 X 0 = 9 X 16.0 = 144.0 Sum = 27.0 + 42.0 + 144.0 = 213.0