The Mole Concept:



|The Mole Concept: |      [pic] |

[pic]There will be a formal test before Lab Day. You will demonstrate on this test that you can convert grams to moles, moles to molecules, and molecules to grams. Your paper periodic table and a "hand-held" calculator may be used during the test, but nothing else.

|[pic]A Mole Is: |

|6.02 x 1023 of anything. |

|The formula mass in grams of a substance contains one mole of particles. |

|Na = Avogadroës Number = 6.02 x 1023 |

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| |[pic]The mole is important because: | |

| |It allows us to weigh atoms in the lab. | |

| |It allows us to compare amounts of atoms in chemical reactions. | |

Basic mole calculations: convert mass to moles, and moles to molecules or atoms.

|[pic] |The following equalities are used in mole calculations: |

1 mole = 6.02 x 1023 atoms or molecules = formula mass in grams

 

|Examples of Mole Conversion Problems: |

|These problems are set up correctly using Factor Label. Use a calculator to find each answer with the proper number of significant digits. |

|Given 12.011 grams of carbon, how many atoms do you have? |

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|Given 18 grams of water, how many molecules do you have? |

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|Given 3.5 moles of sodium chloride, how many grams do you have? |

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|What is the mass of 6.02 x 1023 molecules of silver nitrate? |

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|[pic] |[pic]Setting up the factor-label problem is just as important as the answer. |

| |[pic]Form the habit of working neatly, canceling units, and circling the answer. |

| |[pic]Remember, units are just as important as numbers in the answer. |

|Mole Calculation Practice Problems. |

|Show the factor-label calculation used to work each problem. |

|What is the mass in grams of 0.452 mole of C6H12O6? |

|Calculate the mass in kilograms of 0.681 mole of ammonia gas, NH3. |

|Determine the number of potassium ions in 3.05 mole of K+. |

|How many molecules are in 39.0 grams of Fe2S3? |

|Calculate the mass in grams of 2.23 moles of nitrogen molecules. |

|How many atoms are in 6.4 grams of copper? |

|A raindrop contains about 0.05 grams of water. |

|How many molecules of water are in a raindrop? |

|How many atoms of hydrogen are in a raindrop? |

|How many atoms of oxygen are in a raindrop? |

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