应用化学专业英语 教学课件 ppt 作者 黄忠 谢普会 付颖 主编Lesson 2 nomenclature of inorganic compounds 1课件.ppt

Copyright ? Houghton Mifflin Company Forms of Chemical Bonds There are 3 forms bonding atoms: Ionic—complete transfer of 1 or more electrons from one atom to another (one loses, the other gains) Covalent—some valence electrons shared between atoms _________ – holds atoms of a metal together Common Names A lot of chemicals have common names as well as the proper IUPAC name. Chemicals that should always be named by common name and never named by the IUPAC method are: H2O water, not dihydrogen monoxide NH3 ammonia, not nitrogen trihydride COMPOUNDS FORMED FROM IONS Na+ + Cl- -- NaCl Properties of Ionic CompoundsForming NaCl from Na and Cl2 A metal atom can transfer an electron to a nonmetal. The resulting cation and anion are attracted to each other by electrostatic forces. IONIC COMPOUNDS Some Ionic Compounds Mg2+ + N-3 ---- Mg3N2 magnesium nitride Sn4+ + O2- ---- SnO2 Tin (IV) oxide Formulas of Ionic Compounds Formulas of ionic compounds are determined from the charges on the ions atoms ions ? ? ? ? – Na ? + ? F : ?? Na+ : F : ?? NaF ? ? ? ? sodium + fluorine sodium fluoride formula Charge balance: 1+ 1- = 0 Monatomic Ions Writing a Formula Write the formula for the ionic compound that will form between Ba2+ and Cl?. Solution: 1. Balance charge with + and – ions 2. Write the positive ion of metal first, and the negative ion Ba2+ Cl? Cl? 3. Write the number of ions needed as subscripts BaCl2 Learning Check Write the correct formula for the compounds containing the following ions: 1. Na+, S2- a) NaS b) Na2S c) NaS2 2. Al3+, Cl- a) AlCl3 b) AlCl c) Al3Cl 3. Mg2+, N3- a) MgN b) Mg2N3 c) Mg3N2 Solution 1. Na+, S2- b) Na2S 2. Al3