ch3 - Molecules, Compounds & Equations Chapter Goals...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Molecules, Compounds NaCl, salt Buckyball, C 60 Ethanol, C 2 H 6 O Chapter 3 Chapter Goals Interpret, predict, and write formulas for ionic and molecular compounds Nomenclature Properties of ionic compounds More on molar mass Percent composition and derivation of formulas from experimental data. Elements that exist as molecules Atoms of most of the nonmetals form discrete molecules, except for the noble gases: H 2 , O 2 , N 2 , F 2 , Cl 2 , Br 2 ( l), I 2 (s) Some elements can exist in more than one form of molecule; the different forms are called allotropes . Examples are: Diamond, graphite, and buckyballs for carbon. O 2 and O 3 (ozone) for oxygen. Allotropes of C Atomic Solids (molecules) ELEMENTS THAT EXIST AS POLYATOMIC MOLECULES White P 4 and polymeric red phosphorus (P 4 units) Sulfur: crown- shaped rings of S 8 molecules Molecular Compounds: Formulas NAME MOLECULAR CONDENSED STRUCTURAL FORMULA FORMULA FORMULA Ethanol C 2 H 6 O CH 3 CH 2 OH C O C H H H H H H C C H H O H H H H Dimethyl C 2 H 6 O CH 3 OCH 3 ether Ethanol and dimethyl ether are constitutional isomers.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Ionic compounds consist of cation (metal) and anions (1 or 2 nonmetallic elements). have attractions called ionic bonds between positively ( cations ) and negatively charged ions ( anions ). have high melting and boiling points. are solids at room temperature. have no net charge Monatomic Cations Group 1 (1A) metals lose one electron to produce a mono-positive ion Na Na + + e- 11 p + 11 p + 11 e - 10 e - Monatomic Cations Metal atoms of group 2A lose two electrons to produce di-positive ions Mg Mg 2+ + 2e- Monatomic Anions Nonmetals often gain one or more electrons and form ions having a negative charge equal to 8 minus the group number of the element: Group Atom # e - gained anion 5A N 3 e - N 3- P P 3- 6A O 2 e - O 2- S S 2- 7A F 1e - F - Cl, Br, I Cl , Br , I Transition Metals form Positive Ions Most transition metals and Group 4A (14) metals form 2 or more positive ions. Zn, Ag, and Cd form only one ion . Names of Some Common Ions Main group metals Nonmetal : change the last element name only part of the name to ide
Background image of page 2
Naming Cations transition metals and In, Sn, Tl, Pb, Bi new system: element name (charge in Roman numerals) eg. Mn 2+ manganese(II) Mn 3+ manganese(III) Cr 2+ - Cr 3+ chromium(III) Fe 2+ iron(II) Fe 3+ - Exceptions: when only one cation Ag + silver Zn 2+ zinc Cd 2+ cadmium Polyatomic Ions A polyatomic ion is a group of atoms. has an overall positive or negative charge. Polyatomic Ions (learn) Some examples of polyatomic ions are NH 4 + ammonium H 3 O + hydronium OH hydroxide N 3 azide CO 3 2− carbonate CN cyanide CH 3 CO 2 acetate C 2 O 4 2− oxalate NO 3 nitrate NO 2 nitrite PO 4 3− phosphate PO 3 3− phosphite SO 4 2− sulfate SO 3 2− sulfite CrO 4 2− chromate Cr 2 O 7 2− dichromate MnO 4 permanganate MnO 4 2− manganate Hydrogenated Polyatomic Ions
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/08/2010 for the course CHM 2045 taught by Professor Vxv during the Spring '10 term at College of the Canyons.

Page1 / 13

ch3 - Molecules, Compounds & Equations Chapter Goals...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online