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Learn about atomic, molecular, and formula masses, and how to calculate them. Explore the importance of Vitamin A and its molecular mass. Practice calculating formula masses with examples like Calcium Phosphate. Get ready for homework on molecular and formula masses.
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Chapter 8 Molecular & Formula Masses
Atomic mass • The atomic mass is the average mass of an atom.
When using atomic masses make sure to round to at least one decimal place.
What is the atomic mass of actinium (Ac)? 227.0278 227.0
What is the atomic mass of hydrogen (H)? 1.00794 1.0
Vitamin A: C20H30O • The first of the 13 vitamins to be discovered, it plays a vital role in the growth and repair of body tissues, and is particularly important in maintaining good eyesight and healthy skin, as well as aiding in bone and teeth formation. • Vitamin A-rich foods include: Liver, sweet potatoes, carrots, mangoes, spinach, cantaloupe, dried apricots, milk, egg yolks, mozzarella cheese.
Determine the Molecular Mass of Vitamin A C20H30O 20 x 12.0 = 240.0 30 x 1.0 = 30.0 1 x 16.0 = 16.0 = 286.0 amu
H H2O NaCl • H is an atom and it would therefore have an atomic mass. • H2O is a molecule and it would therefore have a molecular mass. • NaCl is neither an atom or a molecule and would therefore have a formula mass.
Formula Mass • The formula mass is the mass of an ionic compound. • An ionic compound is formed from a combination of metals and nonmetals. • Formula masses are calculated the same as molecular masses.
Determine the Formula Mass of Calcium Phosphate Ca3(PO4)2 3 x 40.1 = 120.3 2 x 31.0 = 62.0 8 x 16.0 = 128.0 = 310.3 amu
Homework • Molecular and Formula Mass Worksheet (due in two days). • Don’t forget to show your work on your calculations.