Naming Compounds and Writing Formulas

1. Naming Compounds and Writing Formulas

2. Key Question: Why Do Atoms Combine In Certain Ratios?

3. Review of Oxidation Numbers

4. Chemical Compound Quiz Sodium chloride is a flavorful addition to many foods. What is the common name? Salt

5. Review of Oxidation Numbers All compounds have an electrical charge of zero (they are neutral). An oxidation number indicates the charge on the atom (or ion) when electrons are lost, gained, or shared in chemical bonds.

6. Oxidation Numbers A sodium atom always ionizes to become Na+ (a charge of +1) when it combines with other atoms to make a compound. Therefore, we say that sodium has an oxidation number of 1+. What is chlorine’s oxidation number?

8. H He Li Be B C N O F Ne Na Mg Al Si P S ClAr 1 2 3 4 5 6 7 8 Valence Electrons ------------------------ The Number Of Electrons In The Outside Energy Level.

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10. Ionic Bonds On the periodic table, strong electrondonorsare on the left side (alkali metals). Strong electron acceptors are on the right side (halogens). The further apart two elements are on the periodic table, the more likely they are to form an ionic compound.

12. Covalent Bonds Covalent compounds form when elements have roughly equal tendencies to accept electrons. Elements that are both nonmetals and therefore close together on the periodic table tend to form covalent compounds.

13. Oxidation Numbers, Lewis Structures And Chemical Formulas Remember, the oxidation numbers for all the atoms in a compound must add up to zero.

14. Multiple Oxidation Numbers Some periodic tables list multiple oxidation numbers for most elements. This is because more complex bonding is possible.

15. Naming Compounds and Writing Formulas

16. Naming Binary Ionic Compounds:At the conclusion of our time together, you should be able to: Name a binary ionic compound with a metal that has one oxidation number using standard naming procedures Name a binary ionic compound with a metal that has multiple oxidation numbers using the Roman system Write the formula of a binary ionic compound if given the name

17. 6 Types Of Chemical Compounds • Binary ionic - metal ion – nonmetal ion • Binary molecular - two nonmetals • Ternary ionic - at least one ion is a polyatomic ion • Binary acid - H – nonmetal • Ternary acid - H – Polyatomic ion • Base - metal ion – OH

18. Naming Compounds with Ionic Bonds

19. Tips To Keep In Mind When Naming And Writing Formulas: • Always keep your Periodic Table handy – You should have it in front of you ALWAYS when you are naming and writing formulas. • Remember that metals (except Hydrogen) are found to the left of the stairstep on the Periodic Table. • Nonmetals are found on the right side of the stairstep of the Periodic Table. • Metalloids are the 6 elements on or below the stairstep except Al, Po and At. For naming purposes they will tend to behave like nonmetals.

21. Naming Binary Compounds A binary ionic compoundis held together by ionic bonds. Binary molecular compoundsconsist of covalently bonded atoms. Each type of compound has its own naming rules.

22. How Do You Name Binary Ionic Compounds? • (Composed Of Two Elements – A Metal And A Nonmetal) • Name the first ion • From groups 1, 2, 3, 13, zinc, cadmium, or silver. (You must use a Roman Numeral with the name for the other metals – we’ll discuss this later.) • Name the second ion changing the suffix to –ide.

23. Naming Binary Ionic Compounds MgBr2 is magnesium(name of first element) + brom(root name of second element) + idesuffix = magnesium bromide

24. Examples NaCl Sodium Chloride Name the metal ion CaO Name the nonmetal ion, changing the suffix to –ide. Oxide Calcium Al2S3 Aluminum Sulfide MgI2 Magnesium Iodide

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26. Examples This is two metals – not a binary ionic compound BaNa2 You should recognize a problem with this one The name of this is Banana (haha!!) What is the name of this compound: HIJKLMNO? WATER – “H” to “O” You have to admit – that was funny!

27. Exit Quiz LiCl Lithium Chloride Name the metal ion CaSe Name the nonmetal ion, changing the suffix to –ide. Selenide Calcium Ga2S3 Gallium Sulfide MgF2 Magnesium Fluoride

28. What About The Transition Metals And Using Roman Numerals? How Does That Work? Let’s See. Notice – metal and nonmetal. FeO Name the first ion. Since the first ion is a transitionelement, you must use a Roman Numeral to represent the charge. Iron (II) Oxide How do you know the charge? Deductive reasoning. • All compounds are neutral. • Oxygen has a -2 charge (group 16) • Therefore, iron must have a +2 charge since there is one iron and one oxygen. Iron gets a Roman Numeral (II). Isn’t this easy and FUN!!!

29. Name the first ion. Since it is a transition metal, you must use a Roman Numeral. • Which Roman Numeral? The Roman Numeral is the same as the charge of the ion. • How do you find the charge? • Deductive reasoning! • All compounds are neutral • Sulfur has a -2 charge (group 16) • There are two coppers • Therefore each copper must have a +1 charge for the compound to be neutral Cu2S Copper (I) Sulfide

30. MnO2 • Name the first ion. Since it is a transition metal, you must use a Roman Numeral. • How do you determine the Roman Numeral? • It is the same as the charge. • What is the charge of Mn? • Oxygen (group 16) has a -2 charge and a total of -4 charge. • There are two oxygens with one manganese. • Therefore Mn must have a +4 charge for this compound to be neutral. Manganese (IV) oxide

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32. So Why Must We Use Roman Numerals With Transition Elements? • The metals in groups 1, 2, 3, and 13 have single, definite charges. • Group 1 metals have a +1 charge. • Group 2 metals have a +2charge. • Groups 3 and 13 metals have a +3charge. • Transition metals may have multiple charges – usually two different positive charges. • For example, there are two copper oxide compounds: ____ Copper (II) oxide Copper is +2 _____ Copper (I ) oxide Copper is +1 Cu2O and CuO We can’t just say Copper oxide. Which one of these is Copper oxide? We must distinguish these by using a Roman Numeral

33. And Remember, There Are Three Transition Elements Which Do Not Require A Roman Numeral Because They Have Single Definite Charges. These Are: Zinc – Zn2+ Cadmium – Cd2+ Silver – Ag+ You need to remember the charges for these. Ag2O Name the first ion. Name the second ion changing the suffix to –ide. Silver oxide No Roman Numerals needed for these. ZnCl2 Name the first ion. Name the second ion changing the suffix to –ide. Zinc chloride

34. How Do You Write Formulas For Binary Ionic Compounds Given The Name? • Two Simple Steps: • Write the symbol and charge of each ion • Balance the charges by providing subscripts Magnesium chloride Write the symbol and charge of each ion Mg2+ Cl- Balance the charges by supplying subscripts. Subscripts tell how many of each atom is present. Cl- MgCl2 You need a second Cl-1 to balance the charges

35. Iron (III) bromide Fe3+ Br - Write the symbol and charge of each ion. The charge of the iron is provided by the Roman Numeral. Br - Br - FeBr3 Balance the charges by supplying subscripts. The subscripts tell how many of each ion is needed to balance the compound. You’ll need three bromine ions to balance the one iron.

36. Aluminum Sulfide Write the symbol and charge of each ion. Al3+ S2- Balance the charges by supplying subscripts. Al3+ S2- In this case the charges do not evenly divide into each other. You must find the least common multiple. SIX S2- Al2S3 How many aluminums are needed to arrive at a +6 charge? 2 How many sulfurs are needed to arrive at a -6 charge? 3

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38. Writing Formulas a Little Quicker Iron and oxygen combine to form a compound. Iron (Fe) has an oxidation number of 3+. Oxygen (O) has an oxidation number of 2–. Predict the chemical formula of this compound.

39. Writing Formulas a Little Quicker 2- 3+ Fe O 2 3 Simply cross the oxidation numbers and make them positive

40. Let’s Try Another One: Manganese (IV) phosphide 3- 4+ Mn P 3 4

41. Let’s Try One More: Manganese (IV) oxide Cross but in this case they must be dropped! 2- 4+ Mn O 2 4 MnO2

42. Naming Binary Ionic Compounds:Let’s see if you can: Name a binary ionic compound with a metal that has one oxidation number using standard naming procedures Name a binary ionic compound with a metal that has multiple oxidation numbers using the Roman system Write the formula of a binary ionic compound if given the name

43. Exit Quiz – Formula for magnesium chloride? 2+ 1- MgCl2

44. Exit Quiz – Formula for sodium oxide? 1+ 2- Na2O

45. Exit Quiz – Name for: 6+ 6- 3+ 2- Fe2O3 Iron (III) oxide

46. Exit Quiz: Formula for Chromium (IV) oxide 4+ 2- Cr O 2 4 CrO2

47. Murphy's LawsofScience and Technology Logic is a systematic method of coming to the wrong conclusion with confidence.

48. Naming Compounds and Writing Formulas II

49. 6 Types Of Chemical Compounds • Binary ionic - metal ion – nonmetal ion • Binary molecular - two nonmetals • Ternary ionic - at least one ion is a polyatomic ion • Binary acid - H – nonmetal • Ternary acid - H – Polyatomic ion • Base - metal ion – OH

50. Naming Binary Molecular and Ternary Ionic Compounds:At the conclusion of our time together, you should be able to: Name a binary molecular compound Name a ternary ionic compound with a metal that has one and multiple oxidation numbers using the appropriate system Write the formula of a binary molecular and ternary ionic compound if given the name