Nomenclature The substance behind the name

Now what was the correct ingredient… sodium chloride or sodium cyanide ? Oh well, what is in a name anyway…Ha…Ha..Ha Now what was the correct ingredient… sodium chloride or sodium cyanide ? Oh well, what is in a name anyway…Ha…Ha..Ha

Thought Map for Nomenclature When given a molecular formula ask the question, “what kind of compound is this?” If it is a molecular binary compound (nonmetal-nonmetal) then we will use the “prefix” system If it is an ionic binary compound (metal-nonmetal) then we will use the standard system with the insertion of a roman numeral where necessary. If it is a ternary compound then we will use the same system as the ionic binary but the ending will be modified to reflect the polyatomic ion associated with the metal.

Metallic Politics Zachmann refers to the alkaline metals and the alkaline earth metals as “conservatives.” The term is used to remind the students that these metals tend to show only one valence destiny. Zachmann refers to the alkaline metals and the alkaline earth metals as “conservatives.” The term is used to remind the students that these metals tend to show only one valence destiny. The transition metals can use the d-orbitals to expand the valence shell. Since they can have many possible valences they are called “liberals.” The transition metals can use the d-orbitals to expand the valence shell. Since they can have many possible valences they are called “liberals.” The main point to keep in mind is that when a transition metal is in the compound then the name must include the exact valence of the metal in the name. The main point to keep in mind is that when a transition metal is in the compound then the name must include the exact valence of the metal in the name.

Name CaCl 2 Following the protocol for naming we ask “what kind of compound is this?” Since it is a binary compound we must then ask “what kind of binary compound is it?” Since it is a metal-nonmetal binary we must ask “do I need to include the valence of the metal?” Since calcium is a “conservative” metal we do not need to include the valence of the metal in the name. Therefore the name is calcium chloride.

Name Cu 2 O Following the protocol for naming we ask “what kind of compound is this?” Since it is a binary compound we must then ask “what kind of binary compound is it?” Since it is a metal-nonmetal binary we must ask “do I need to include the valence of the metal?” Since copper is “liberal” metal we do need to include the valence of the metal in the name. We must then ask “what is the valence of this metal.” By the reverse crisscross method and validation of the nonmetal valence we find the valence of Cu to be 1. Therefore the name is copper I oxide.

Name CuO Following the protocol for naming we ask “what kind of compound is this?” Since it is a binary compound we must then ask “what kind of binary compound is it?” Since it is a metal-nonmetal binary we must ask “do I need to include the valence of the metal?” Since copper is “liberal” metal we do need to include the valence of the metal in the name. We must then ask “what is the valence of this metal.” By the reverse crisscross method and validation of the nonmetal valence we find the valence of Cu to be 2. Therefore the name is copper II oxide.

Name N 2 O 5 Following the protocol for naming we ask “what kind of compound is this?” Since it is a binary compound we must then ask “what kind of binary compound is it?” Since it is a nonmetal-nonmetal binary we can name the compound by simply identifying the frequency of each atom with a prefix. Since nitrogen appears two times and oxygen appears five times we use the respective prefixes di and penta. Therefore the name is dinitrogen pentoxide.

Name Fe 3 (PO 4 ) 2 Following the protocol for naming we ask “what kind of compound is this?” Since it is a ternary compound we must approach it like a ionic binary compound. Since it has a metal component we must ask “do I need to include the valence of the metal?” Since iron is “liberal” metal we do need to include the valence of the metal in the name. We must then ask “what is the valence of this metal.” By the reverse crisscross method and validation of the nonmetal valence we find the valence of Fe to be 2. Therefore the name is iron II phosphate.

Finding Valence from a Formula As instructed in class we simply reverse the crisscross. With this method the subscript of the neighboring element (or polyatomic ion) becomes the probable valence. To be sure you must always validate the “probable” valence of the nonmetal component. To do this just form a ratio with the probable valence as the denominator and the valence destiny value as the numerator. Now, set this ratio equal to the comparable ratio for the metal component and solve for the unknown numerator value for the metal.

Find Valence of Cu and O in CuO The subscripts are both 1. By reverse crisscross we get a “probable” valence of 1 for oxygen and a “probable” valence of 1 for Cu. Now the valence destiny of oxygen according to ASIMS is 2 thus our equation becomes: (X)/1 = 2/1 and solving for x we get 2.

Ok, now that you are all charged up don’t let the cat get your tongue, name this compound!... SO 3 Yes, it is sulfur trioxide. The valences of S and O are 6 and 2 respectively.

Find Valence of C and O in CO 2 The subscripts C and O are 1 and 2 respectively. By reverse crisscross we get a “probable” valence of 1 for oxygen and a “probable” valence of 2 for C. Now the valence destiny of oxygen according to ASIMS is 2 thus our equation becomes: (X)/2 = 2/1 and solving for x we get 4. The valence of carbon is 4 and that of oxygen is 2.

Reminders for the Quiz From the homework problems and this reminder review you now know the exact skills that the quiz and or exam will assess. Given a formula be able to name it. Given a name be able to write the formula for the name. Given a formula be able to determine the valence of each component by the method of reverse crisscross/validation.