Formulas and Names of Compounds Chapter 3

Game Plan Day 1: Lesson 1 and Lesson 2 Day 2: Lab: Fe+2/Fe+3 Day 3: Lesson 3 and Lesson 4 Day 4: Lesson 5 and Review Day 5: Test on nomenclature

Day 1: Lesson 1: Molecular Compounds and Formulas Read/notes lesson 1 which begins on page 86

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Day 1:Molecular Compounds and Formulas An element is just one type of atom A compound is 2 or more elements that are bonded. 1) Molecular compounds: 2 or more elements bonded by sharing electrons. Nonmetal to nonmetal….Bonding = ? 2) Ionic compounds: 2 or more elements bonded by transferring electrons. Metal to nonmetal …..Bonding = ?

Clues in the names Binary compounds contain only two kinds of atoms. These compounds end in “ide”. Tertiary compounds contain more than two kinds of atoms. These compounds usually end in “ate” or “ite”

Binary Molecules Prefixes PrefixNumber of atoms mono-1 di-2 tri-3 tetra-4 penta-5 hexa-6 hepta-7 octa-8 nona-9 deca-10

Rules for writing formulas for molecules =) 1. Write the chemical symbol for each element mentioned- in the order given in the name. 2. Add subscripts according to the prefixes in the name. A subscript goes on the right side of its symbol. When there is no prefix or the prefix is mono-, do not write any subscript.

Practice: Write the formulas for these binary molecules 1. Silicon dioxide 2. Carbon monoxide 3. dinitrogen pentasulfide 4. Sulfur hexafluoride 5. tetraphosphorus decoxide

What is a molecule? A molecule is a neutral group of atoms that are bonded together by sharing electrons…Covalent bond The smallest unit of a molecular compound is a molecule. Example: One molecule of carbon tetrachloride, CCl 4, contains 1 carbon atom and 4 chlorine atoms.

Molecule vs Molecular Compound The atoms in a molecule may be of the same element (such as Cl 2 ) or different elements (such as CCl 4 ). Note: A sample of Cl 2 is a molecule but not a molecular compound because a compound contains 2 or more different elements. There is only one element in Cl 2. Chlorine gas is the most widely used disinfectant of water and food processing systems. The German Army first used chlorine gas cylinders in April 1915 against the French Army at YpresGerman Army French ArmyYpres

Lesson 1 Review Turn to page 90 in the chemistry book. Complete the Lesson 1 Review. You need to write complete sentences in answering each question 1-10

Day 2: Lab on Fe +2 /Fe +3

Day 3: Lessons 2,3 Lesson 2: Ions and Ionic Compounds Lesson 3: Ionic Compounds and Formulas

Ions When an atom gains or loses electrons, they are no longer neutral….they are a charged particle called an “ion”. These ions are the electrolytes in sports drinks. Like K +1 or Na +1 Metals lose electrons to become a + charged ion called a cation. Nonmetals gain electron(s) to become a – charged ion called an anion.

Ionic Compounds Ionic compounds consist of a cation and an anion. Ionic compound = cation + anion Sodium chloride = sodium + chloride cation anion Sodium chloride = Na + + Cl - = NaCl

Charges on ions

Write the ions for the following elements by writing the symbol…. then the charge. Example: Sodium NaNa +1 1) Aluminum6) Barium 2) Fluorine7) Nitrogen 3) Magnesium8) Lithium 4) Rubidium9) Potassium 5) Oxygen 10) Sulfur

Special case: transition metals These guys can have several charges just like you realized in lab…Fe +2 and Fe +3 ions. So for these elements you have to be given the charge! In Iron (II) sulfide, the cation is iron +2 In Iron (III) sulfide, the cation is iron +3

Write the ions for the following elements by writing the symbol…. then the charge. 1)Copper (II) 2)Cadmium (II) 3)Manganese (IV) 4)Scandium (III) 5)Chromium (IV) Read “Spotlight on Iron” on page 95. What ion of iron is found in your blood?

Lesson 2 : Review Answer questions on page 96…For the matching write the word then its definition.

Lesson 3: Formula Units The smallest form of an ionic compound is called a formula unit…lowest ratio of atoms. Compare Ca 4 Cl 8 and CaCl 2 Ionic compounds contain positive and negative ions. However, all ionic compounds are electrically neutral. This means the total positive charge equals the total negative charge!

How to write formulas for ionic compounds. Write symbols Write charges Cross over Reduce…if necessary 1)Calcium chloride3)Tin (IV) oxide 2)Aluminum sulfide 4) Iron (III) oxide

Lesson 3 Review Complete Lesson 3 Review on page 100. Use complete sentences.

Day 4: Lessons 4 and 5

Lesson 4: Polyatomic Ions We have studied compounds containing only 2 elements…these are binary. Now we will look at compounds containing more than 2 elements. These compounds contain polyatomic ions….a group of 2 or more atoms that acts as one ion and has one charge and one name.

Sunglasses Turn to page 101 and read about how sunglasses work!

Polyatomic Ions Act as one group…have one name…have one charge. Turn to page 102 and copy table Some common polyatomic ions

Writing Formulas using polyatomic ions. Write symbols Write charges Cross over Reduce if necessary 1)Barium nitrate4) Ammonium nitrate 2)Sodium carbonate5) Iron (II) Sulfate 3)Lead(II) phosphate6) Potassium chromate

Lesson 4 Review Turn to page 107 and complete the review. Use complete sentences so this will help you on your test!

Lesson 5: Names of compounds We’ll look at how to name molecules…CO 2 We’ll look at how to name ionic solids…NaCl

Molecules: Writing the names from the formula 1. Write the name for the first element in the compound. 2. Then write the name of the second element, but change its ending to –ide. 3. Add prefixes to indicate the number of atoms of each elements. Note : the prefix mono- is dropped for the first element only. Look on page 110 for prefixes.

Practice: Write the name from the formula for these binary molecules 1. N 2 O 4 2. P 2 S 5 3. CO 2 4. H 2 O 5. IF 7

Ionic Solids: Writing the names from the formula 1) Write the name of the cation element or polyatomic ion. 2) Write the name of the anion …end in -ide if an element. If it is a polyatomic ion …don’t mess with its name!!!! Note: if the cation element is a transition metal, include its charge as a Roman Numeral.

Practice: Write the name of these ionic solids from their formula 1) AlBr 3 2) NaCl 3) NH 4 NO 3 4) K 2 O 5) Ca F 2 6) FeCl 3 7) CuSO 4

Acids Acids are compounds that produce H +1 ions when dissolved in water. HCl  H +1 + Cl -1 Extremely corrosive. Inhalation of vapor can cause serious injury. Ingestion may be fatal. Liquid can cause severe damage to skin and eyes. TLV 5 ppm.

Acids Turn to page 115 and copy table in your notes

Lesson 5 Review Turn to page 116 and complete the lesson 5 review. Use complete sentences so this will help you on your test!

Day 5 Review and test

Bibliography