Nomenclature Day 2

1. Nomenclature Day 2 So, I’m sorry I’m not here, but please try your best. I’ve made these notes as straight forward as possible. I will have tutorials Tuesday and Wednesday morning, so you can come in. I have also posted some links to some wonderful youtube tutorials on the website. Your homework is BOTH worksheets… Group B Naming & Formula Writing and Ternary Naming and Formula writing. I know one of them says “PRE-AP” Cross out that phrase if it makes you feel better, but it is due along with the other worksheet, on Wednesday. Be good, and remember to treat your classmates and substitute with kindness and respect. You guys are a pretty awesome bunch; I know you’re going to make me look good! You should have time at the end of class to work on your assignments—please use this time wisely; be as productive as you can! Hopefully, I’ll see you on Wednesday, but you never know with Jury Duty! Make me proud! LOVE, Ms. Morgan

2. Last Time… • We learned that the periodic table is an amazing tool– in addition to being able to use it to determine the number of protons, neutrons, and electrons for any element, we can also determine the number of valence electrons AND the charge for any GROUP A ELEMENT. • Sing it with me! 1,2,3,4, negative 3,2,1! • Have you noticed one of our themes in Chemistry is the awesomeness that is the Periodic Table of Elements?

3. Last Time, continued • We also learned how to use the periodic table to write formulas for and to name the GROUP A BINARY IONIC COMPOUNDS. • They contain a metal and a nonmetal • E.g. Magnesium Chloride • Mg+2 Cl-1 • The NUMBER of the charges are swapped, and used as the subscript for the other element • Mg1Cl2(we don’t actually write the one)… MgCl2 • When naming Group A binary ionic compounds, just give the name of the metal—and then the name of the non-metal with the IDE ending. • NaCl is Sodium Chloride • Ba3N2 is Barium Nitride

4. But What About… • Compounds with GROUP B ELEMENTS? • How do we know their charge? • How do we write formulas for them & how do we name them? • What if a compound has more than just two elements? • How do we write formulas for and name those?

5. Those Funky Group B Metals…What’s the Deal??? +1 0 +2 +/-4 -3 -2 +3 -1 skip a few Group B Elements: They’re FUNKY! Charge Varies

6. Group B—The Transition Metals • The “GROUP B ELEMENTS” are the transition metals. • They’re different from the group A elements we learned about last time because their charges aren’t constant. • Aluminum, a metal in group 3A is ALWAYS +3 • Iron, however, is a group B transition metal, and sometimes it has a +3 charge and other times it has a +2 charge. • Because their charges vary, we must always indicate the charge of the transition metal ion in it’s name. • We do this with roman numerals. • E.g. Fe+2 is Iron (II) • Fe+3 is Iron (III) • This is called the “STOCK SYSTEM” for naming compounds with transition metals. • The classical system is based on the latin names of those metals

7. The Exceptions • Silver, cadmium and zinc’s charges DO NOT VARY. • You do not need to indicate their charge in compounds because it doesn’t ever change. • Silver is always +1 and Cadmium and Zinc are always +2 • Go ahead and WRITE THAT NOW on your periodic table, in the boxes for those elements • Tin (Sn) and lead (Pb) DO have charges that vary, even though they are actually group A elements. • Go ahead and PUT A STARin their boxes on your periodic table to remind you that you MUST use roman numerals to indicate their charge when you are naming compounds with tin or lead.

8. Naming Group B Ionic Compounds • Give the name of the metal and the name of the nonmetal, with the IDE ending • Just like we did before! • BUT, you must determine the charge on the transition metal and put it in the name, using roman numerals • Use the charge on the anion to figure out the charge on the metal • It’s super easy because YOU KNOW that the charges must add up to zero.

9. Example-Group B Naming • E.g. Fe2O3 • So, Iron (something) Oxide • Something = the charge on the Iron: use the anions’ charge to figure it out! • There are three oxide ions, each with a -2 charge, that gives you a total charge from oxide of -6. • You know that Fe2 + -6 = 0 (because the compound is neutral) • So, the TOTAL charge from all the irons must be +6 (because the sum of the charges+6 + -6 equals zero) • You have TWO irons, so each of those must have a charge of +3 (because +3 x 2ions is +6) • SO, the name of the compound is Iron (III) oxide • III = the +3 charge on the iron!

10. More examples… • CuCl • Should be: Copper (something) Chloride • Chloride has a -1 charge • Cu + -1 = 0 • So, in order for the charges to add up to zero, Copper must be +1 • So, the name of the compound is • Copper (I) Chloride

11. More examples, cont’d • SnO2 • Should be Tin (something) Oxide • The oxide ion has a -2 charge, and there are two of them, so total charge from oxide is -4 • Sn + -4 = 0 • So, in order for the charges to add up to zero, Tin must be +4 • So, the name of this compound is Tin (IV) Oxide

12. More examples, cont’d • Mn2S3 • Should be Manganese (something) sulfide • Each sulfide has a -2 charge, and there are three of them, so total charge from sulfide is -6 • Mn2 + -6 = 0 • So, in order for the charges to add up to zero, the TOTAL charge from the two Manganese ions needs to be +6. • There are two Manganese ions, so each one must have a charge of +3 • So, the name of this compound is Manganese (III) Sulfide.

13. Try These! • Cr2S3 • GaN • PbF2 • Cu3N2 • Fe2S3

14. And, the answers are… • Chromium (III) Sulfide • Gallium (III) Nitride • Lead (II) Fluoride • Copper (II) Nitride • Iron (III) Sulfide

15. Writing formulas for Group B Compounds • Exactly the same as how you wrote formulas for group A, only you don’t use the periodic table to determine the charge of the metal. • Use the roman numeral! • For example: Lead (II) Nitride • Pb+2 N-3 • Swap the numbers and the formula is: • Pb3N2

16. Try These! Write the formulas for the following Group B-Binary Ionic Compounds. • Copper (I) Bromide • Lead (IV) Oxide • Chromium (III) Chloride • Iron (III) Sulfide • Nickel (II) Fluoride

17. And, the answers are… • CuBr • PbO2 • CrCl3 • Fe2S3 • NiF2

18. Ternary Ionic Compounds • One of the Questions we asked ourselves earlier was: • How do we write formulas for and name compounds that have MORE than just two elements? • These are called ternary ionic compounds • They contain three or more different elements • They usually contain a polyatomic ion

19. Polyatomic Ions • “Poly” means “many” • Polyatomic means “many atoms” • These are just groups of atoms that act as a single unit and carry a charge • They usually end in ITE or ATE, but there are a few exceptions • “OH-” is hydroxide • “NH4+” is ammonium • “CN-” is cyanide • There is a chart on the very back page of your notes packet that has all of the polyatomic ions and their charges. • You’re going to need to start memorizing the major ones • Nitrate, Sulfate, Phosphate, Chromate, Dichromate, Carbonate, Chlorate, Ammonium and Hydroxide • The “ites” have one fewer oxygen than the “ates”

21. Naming Ternary Ionic Compounds • When naming compounds that have polyatomic ions: • Give the name of the metal • Put the charge of the metal in roman numerals IF AND ONLY IF THE METAL IS A TRANSITION METAL • Give the name of the polyatomic ion • You get that name from the chart on the back page of your notes packet • AND THAT’S ALL THERE IS TO IT!

22. Writing Formulas for Ternary Ionic Compounds • First off, you know you have a “ternary” if: • The first part of the name says “ammonium” • OR if it ends in “ite,” “ate” or the two exceptions I mentioned before (cyanide, or hydroxide) • If this is the case, look up your poly in the polyatomic ion chart!

23. Writing Formulas for Ternary Ionic Compounds cont’d • Write down the symbols for each element or polyatomic ion. • Find the charge of the element and the polyatomic ion and write them above and to the right of each element or polyatomic Ex: Calcium Nitrate Ca NO3 Ca+2 NO3-1 (You get Ca’s charge from Ptable and NO3’s from your poly chart)

24. Take the numerical charge of each ion and swap them just like we’ve done before. • If the number you put after the polyatomic is larger than one, put the polyatomic ion in parenthesis, then place the number outside of the parenthesis. Don’t forget to simplify, if you can! Ca+2 NO3-1… Ca1(NO3)2 You put the parenthesis because you need 2 NITRATES—two of the whole polyatomic ion. Think of it like a group of friends that like to stick together!

25. Try It! Write the formulas for the following ternary compounds: • NH4+, SO3-2 • Calcium ion, phosphate ion • Al3+, NO3-1 • Potassium ion, chromate ion • Lithium sulfate • Chromium (III) nitrite • Magnesium Hydroxide

26. And, the answers are… • (NH4)2SO3 • Ca3(PO4)2 • Al(NO3)3 • K2CrO4 • Li2SO4 • Cr(NO2)3 • Mg(OH)2

27. And that’s all there is to it, folks!FAQ’s • How do I know if I need to use roman numerals? • ONLY if you have a group B transition metal OR if the metal is tin (Sn) or lead (Pb) • ONLY use them in the NAME e.g. Iron (III) Oxide • DO NOT use roman numerals for silver, cadmium or zinc (their charges don’t change) or any other metals! • How do I know if the metal is a transition metal? • You look at the periodic table, and it’s in the “middle” • It’s a “GROUP B” metal • How do I know what roman numeral to use? • It’s based on the anion’s charge • The total charge on the cation must cancel the anions charge (the sum of all the charges must be zero). See earlier slide “Naming Group B Ionic Compounds.” • How do I know if there is a polyatomic ion? • If you’re going from a formula to a name, you would know because there are three or more different elements present • If you’re going from a name to a formula, you know because the name ends in either “ite” or “ate.” Remember: ammonium, cyanide, and hydroxide are also polyatomic ions. • How do I know if I need to use parenthesis? • IF you are writing a formula for a compound that has a polyatomic ion, and you need MORE THAN ONE of that polyatomic ion in the formula (after you’ve swapped the charges)