Molar Mass
ATOMIC MASS Mass of an atom in atomic mass units (amu) Ex: Carbon = amu Molecular mass—sum of atomic masses (in amu) in the molecule Ex: Water = 2 (1.01 amu) amu = amu Formula mass—sum of the atomic masses (in amu) in the formula unit of an ionic compound EX: sodium chloride = amu amu = 58.44amu
MOLAR MASS Mass (in grams) of 1 mole of particles of a substance Numerically equal to the atomic mass Ex: water = g C 8 H 11 NO 2 = magnesium phosphate =
Dimensional Analysis Examples i. Calculate the mass in grams of moles of chromium.
ii. What is the mass of 4.35 moles of sulfuric acid H 2 SO 4 ?
iii. Calculate the number of moles of 321 g of lead(II) chloride.
iv. How many formula units are in 124 g of mercury(II) chloride?
v. What is the mass in grams of 1.50×10 15 molecules of sulfur dioxide?
vi. A sample of aluminum chloride has a mass of 35.6 g. 1. How many moles of chloride ions are present? 1. How many chloride ions are present
vii. How many oxygen atoms are in 37.5 grams of SO 3 ?