1 / 22

Nomenclature Review and the MOLE

Nomenclature Review and the MOLE. September 19 2011. Reviewing the atom. ATOM – smallest piece of an element. Nucleus Very dense, almost all the mass of the atom, but very small Protons – positively charged, one AMU Neutrons – no charge (neutral), one AMU Energy levels

Download Presentation

Nomenclature Review and the MOLE

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Nomenclature Review and the MOLE September 19 2011

  2. Reviewing the atom • ATOM – smallest piece of an element

  3. Nucleus • Very dense, almost all the mass of the atom, but very small • Protons – positively charged, one AMU • Neutrons – no charge (neutral), one AMU • Energy levels • Electrons – e- -negatively charged, very small • First energy level – only two electrons • Later energy levels – eight electrons

  4. Name that atom…

  5. Atoms and Ions • ATOMS – smallest piece of an element • GROUND STATE – overall zero charge • Equal numbers of protons and electrons • IONS – atoms with charges! • Electrons have been stolen… the imbalance of protons (positive) and electrons (negative) results in a charged particle

  6. Atoms and Ions • Chlorine has 17 protons and 17 electrons • The chloride ion stole an electron from another atom… it now has 17 protons and 18 electrons • It has a negative charge because it has more electrons than protons

  7. Name that atom or ion…

  8. Predicting the charges of ions • How can we determine what charge an ion will have? • The OCTET rule… atoms want to be like noble gases and have eight electrons in their valence (outer) energy level • We can predict charges with groups of the periodic table

  9. Predicting charges… oxidation numbers 0 1+ 1- 2- 2+ 3+ 3-

  10. Polyatomic ions • Groups of atoms that share electrons with each other, but then steal more! • Or electrons they were sharing were stolen from them… • Names do NOT end in -ide 1+

  11. Ions and Ionic Compounds • Ions with opposite charges are attracted to each other like magnets • We call this attraction an ionic bond • Compounds formed by ionic bonds are called ionic compounds • Charges are shown with little numbers up = superscript… K1+ • Numbers of ions in the formula are shown with little numbers down = subscript… O2

  12. How do we name IONIC compounds? • We balance the charges of the ions • Potassium fluoride • K1+ + F1- -> KF • Lithium oxide • Li1+ + O2- -> Li2O • Magnesium bromide • Mg2+ + Br1- -> MgBr2

  13. Ionic and Molecular Compounds

  14. Naming acids • Naming acids is similar to naming ionic compounds… • Cl- is chloride • HCl is hydrochloric acid • SO42- is sulfate • H2SO4 is sulfuric acid

  15. Counting particles… the MOLE • Not this mole…

  16. The MOLE • This mole… 6.02 x 1023

  17. Avogadro • Amedeo Avogadro, 1811 - proposed that the volume of a gas at a given pressure and temperature is proportional to the number of molecules or atoms of the gas, no matter how large or small each atom or molecule is • In other words, more molecules = more volume

  18. Avogadro’s constant • Many scientists… Jean Perrin, JJ Loschmidt, Robert Millikan, Michael Faraday… over many years were involved in experiments that led to the determination of the number of molecules • In 1906, Jean Perrin proposed naming the number in honor of Avogadro… • Avogadro’s number = 6.02 x 1023

  19. The mole and molecular mass • One mole of a substance has a gram mass equal to the atomic mass (AMU)of that substance • Carbon-12 has a mass of 12 AMU • One mole of Carbon-12 has a mass of 12 g • One molecule of H2O has a mass of 18 AMU • One mole of H2O has a mass of 18 g • So if you have 18 g water, you have… 6.02 x 1023 molecules of water

  20. Practice…

  21. Dimensional Analysis • Switching between units • Atomic mass <-> molar mass <-> moles • Kilometers <-> Meters <-> Centimeters Unit conversion factors 100 m = __?__ cm 100 m x 100 cm = 10,000 cm 1 m

  22. Practice… • 1 hour = ______ seconds 1 hr x 60 min x 60 sec = 3600 seconds 1 hr 1 min • 1 year = ______ seconds 1 yr x 365 days x 24 hr x 60 min x 60 sec = 31,536,000 seconds 1 yr 1 day 1 hr 1 min • 60 miles/hr = ________ feet/second 60 mi x 5280 ft x 1 hr x 1 min = 88 feet/sec 1 hr 1 mi 60 min 60 sec

More Related