PPT-The Mole and Avogadro’s Number

Chapter 9 History About 200 years ago scientists needed a unit of measure that connected the mass of a molecule or atom with how many of them there were Amadeo Avogadro proposed his hypothesis in 1811 At that time there was no data on the number of particles in a mole or an agreement on any atomic weights or the standard . A Chemist’s “Dozen”. http://www.ccs.k12.in.us/chsteachers/VKundrat/MOLE_DAY_EXPLOD%5B1%5D.gif. The Mole. The particles that make up matter (ions, atoms, and molecules) are . extremely small. Only large amounts of these particles can be weighed. In order to simplify these large numbers we use . S-C-8-1_The Mole Presentation. Source: http://en.wikipedia.org/wiki/Mole_(animal). The Mole. The mole is a counting unit for chemists, the same way a baker uses a dozen.. 1 dozen = 12 objects. 1 mole = . Unit 18. Avogadro’s Number and the Mole. Significance of Avogadro’s Number (5.3). Size of Avogadro’s Number (5.3). Definition of a Mole (5.3). Formula Mass (and Molecular Mass) (5.3). Introduction to Avogadro’s Number . “A Chemists Dozen”. The Mole – A Chemists Dozen. 1 dozen = . 12 items. 1 six-pack = . 1 hour = . 1 dollar =. 1 mole = . 602,000,000,000,000,000,000,000 entities. Because atoms and molecules are so small, chemists established their own counting unit – the mole. Diagnosis and evaluation of postmolar GTN. Case Scenario . A 21 year old . nulligravida. presents with bleeding during early pregnancy. Last normal menses was 9 weeks ago, home urine pregnancy test was positive 2 weeks ago, and she has been spotting for two days with heavier bleeding the last 6 hours.. The Mole. Chemist’s counting number. amount. of a substance . 1 mole is equal to 6.022 x 10. 23. atoms or particles or molecules (Avogadro’s number). There are always 6.022 x 10. 23 . particles in . Avogadro Memes…. MOLE. (mol)‏. Mass. (g)‏. Particles. (. atoms,m’c. or . f.u. .). MOLE CONVERSIONS. Which conversion factors allow you to convert from mass to moles and from particles to moles.. Avogadro’s Principle – . equal volumes. . of gases at the same temperature and pressure contain . equal numbers of particles. Avogadro’s Formula. . Formula. : . V. 1. . = . V. 2. . . Chemical Quantities. Measuring doughnuts:. 1 dozen = 12 doughnuts (count) . 1 dozen = 500 g doughnuts (mass). 1 dozen = 1 box doughnuts (volume). Measuring steam (H. 2. O gas):. 1 mole = 6.02 x 10. 23 . big. concepts of Chemistry.. The mole is a . counting. number, just like. 1 dozen = . 12. things . 1 score = . 20. things . 1 ream = . 500. things . 1 mole = . 6.022 x 10. 23. . things or . 1 mole of a substance is 6.02 x 10. 23. . representative particles. .. Avogadro’s number = . 6.02 x 10. 23. Avogadro determined the difference between atoms and particles.. Representative particle. 2. structure, and the diborane-like PH. 5. structure predicted by quantum mechanical calculations. Phosphorus atoms are gold, hydrogen atoms are white. Computational Design of Novel Superconductors. 23. How do you measure how much?. You can measure mass, . or volume,. or you can count pieces.. We measure mass in grams.. We measure volume in liters.. We count pieces in . MOLES.. . Counting. . Counting words are used to simplify a description of a number of items. . The amount of a substance that contains:. 6.02 x 10. 23 . particles (atoms, molecules, formula units). . 22.4 L (volume). X grams (molar mass). Put simply:. A mole is a unit of .