Chemical Quantities Chapter 6 Image source:

Atomic Mass & Formula Mass Atomic Mass Formula mass – just what it says it is! Example: –Atomic mass of carbon: 12.01amu –Formula mass of carbon dioxide 1 carbon atom = 12.01amu x 1 atom = oxygen atoms = 16.00amu x 2 atoms = Total = amu for 1 molecule of CO 2

The Mole An experimentally-defined number that is equal to x particles Called Avogadro’s number, after physicist Amedeo Avogadro –600 million trillion particles –Can be atoms, molecules, anything in a distinct unit

The Mole

Molar Mass Quantity in grams that equals the atomic mass of the element or compound For example: What is the molar mass of carbon dioxide? Formula mass = 44.01amu / molecule Molar mass = 44.01g / mole

Chemical Equations Textual representation of a reaction Definitions: Reactant, Product, Coefficient, State of Matter To balance: –1. Write down reactants and products with correct subscripts –2. Add coefficients so that there are the same number of each atom on both sides of the equation –“Least Common Multiples”

Try This! Iron ores such as Fe 2 O 3 are smelted, by reaction with carbon, to form metallic iron and carbon dioxide. Can you write and balance the equation? Can you name the iron ore?

Try This! When propane gas, C 3 H 8, burns in oxygen, it produces water and carbon dioxide. Write and balance the equation.

What Does This Mean? 2Fe 2 O 3 + 3C  3CO 2 + 4Fe 2H 2 (g) + O 2 (g)  2H 2 O(g) Coefficients are proportions of moles –2 moles of iron (III) oxide react with 3 moles of carbon to yield 3 moles of carbon dioxide and 4 moles of iron 2 moles iron (III) oxide 4 moles iron 2 moles iron (III) oxide 3 moles carbon dioxide 3 moles carbon

Try This! Butane, a common fuel in lighters, burns according to the following equation. C 4 H 10 + O 2  CO 2 + H 2 O Balance the equation How many moles of carbon dioxide can I produce if I burn 4 moles of butane?

Mass Calculations

Try This! Write a balanced equation for the following reaction: Aluminum sulfate and sodium hydroxide react to form sodium sulfate and aluminum hydroxide. How many grams of sodium hydroxide are needed to form 18.7 grams of sodium sulfate? If I begin with 25.9g of aluminum sulfate, how many grams of aluminum hydroxide will form?