Chemistry 102 • Dr. Don DeCoste • 367J Noyes Lab • firstname.lastname@example.org • 3-4 pm Tuesdays and Thursdays • By appointment; open door policy • http://chem.illinois.edu
Office Hours No office hours today. Please email me if you’d like to meet with me.
To Do • Continue reading Chapter 3. • Text homework for Chapter 3. • Quiz on Friday (1-3.4) • Lon-Capa assignments #1, 2.
Using The Periodic Table • Symbol, name, number of protons (all of these are related). • Number of electrons in a neutral atom or in ion. • Charges for common ions in a compound. • Metals and non-metals. • Formulas of ionic compounds. • Naming simple compounds.
Three Types of Binary Compounds • Metal (Groups 1,2, 3) and nonmetal • Simple naming: sodium chloride [NaCl]. • Metal (transition) and nonmetal • Roman numerals: cobalt(II) chloride [CoCl2]. • Two nonmetals • Prefixes: carbon dioxide [CO2].
Three Types of Binary Compounds • Na2O • Cu2O • N2O
Type I Compound Na2O sodium oxide
Type II Compound Cu2O copper(I) oxide
Type III Compound N2O: dinitrogen monoxide
Type III Compound N2O5 dinitrogenpentoxide
Clicker Question How many of the following is/are named incorrectly? I. PCl3 phosphorus(III) chloride II. KCl potassium monochloride III. CoO cobalt oxide IV. Fe2O3 iron(II) trioxide a) 0 b) 1 c) 2 d) 3 e) 4
Clicker Question These are correct: I. PCl3 phosphorus trichloride II. KCl potassium chloride III. CoO cobalt(II) oxide IV. Fe2O3 iron(III) oxide
Clicker Question The mass of a single atom of hydrogen is: a) 1.008 g b) 2.016 g c) 1.000 mole d) 1.674 x 10-24 g e) 6.022 x 1023 g
Clicker Question You have a 12.01 g sample of carbon and a 1.008 gram sample of hydrogen. a) The number of carbon atoms is greater than the number of hydrogen atoms. b) The number of carbon atoms is less than the number of hydrogen atoms. c) The number of carbon atoms is the same as the number of hydrogen atoms.
The Mole Concept: Why? • We can count by weighing (relative masses). • Reactions occur by number of particles, we must deal with masses, so we must have a way of converting between number and mass. • Atoms/molecules are very small!
Clicker Question You have equal mass samples of copper (Cu) and magnesium (Mg). Which sample contains the greater number of atoms? a) The sample of magnesium. b) The sample of copper. c) The samples contain the same number of atoms. d) I have no idea.
A Question For You… You have a 10.0 g sample of copper (Cu). Determine the mass of magnesium (Mg) such that the number of copper atoms equals the number of magnesium atoms.