6 5 Covalent Compounds and Their names Covalent

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6. 5 Covalent Compounds and Their names Covalent compounds= nonmetal + nonmetal, OR metalloid

6. 5 Covalent Compounds and Their names Covalent compounds= nonmetal + nonmetal, OR metalloid + nonmetal Electrons are SHARED to fulfill The octet rule 1 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Electron-Dot Formulas Electron-dot formulas show • the order of bonded atoms in a covalent

Electron-Dot Formulas Electron-dot formulas show • the order of bonded atoms in a covalent compound • the bonding pairs of electrons between atoms • the unshared (lone pair) valence electrons • a central atom with an octet 2 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Electron-Dot Formulas and Models of Some Covalent Compounds (also called molecular compounds) Central atom

Electron-Dot Formulas and Models of Some Covalent Compounds (also called molecular compounds) Central atom Typically written FIRST (H 2 O is the exception) 3 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Names of Covalent Compounds Prefixes are used • in the names of covalent compounds

Names of Covalent Compounds Prefixes are used • in the names of covalent compounds • because two nonmetals can form two or more different compounds Examples of compounds of N and O: NO nitrogen monoxide (the book is wrong on this one) NO 2 nitrogen dioxide N 2 O dinitrogen monoxide (the book is wrong on this one) N 2 O 4 dinitrogen tetroxide N 2 O 5 dinitrogen pentoxide 4 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Guide to Naming Covalent Compounds 5 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Guide to Naming Covalent Compounds 5 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Naming Covalent Compounds To name the covalent compound SO 3, STEP 1 Name the

Naming Covalent Compounds To name the covalent compound SO 3, STEP 1 Name the first nonmetal by its element name. The element S is sulfur. STEP 2 Name the second nonmetal by using the first syllable of its element name followed by ide. O is named oxide. STEP 3 Add prefixes to indicate the number of atoms (subscripts). The subscript 3 of O is shown as the prefix tri. SO 3 → sulfur trioxide The subscript 1(for S) or mono is understood. 6 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Naming Covalent Compounds What is the name of P 4 S 3? STEP 1

Naming Covalent Compounds What is the name of P 4 S 3? STEP 1 Name the first nonmetal by its element name. P is named phosphorus. STEP 2 Name the second nonmetal by using the first syllable of its element name followed by ide. S is named sulfide. STEP 3 Add prefixes to indicate the number of atoms (subscripts). The subscript 4 of P is written as tetra. The subscript 3 of O is written as tri. P 4 S 3 → tetraphosphorus trisulfide 7 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Learning Check Select the correct name for each compound. A. Si. Cl 4 1)

Learning Check Select the correct name for each compound. A. Si. Cl 4 1) silicon chloride 2) tetrasilicon chloride 3) silicon tetrachloride B. P 2 O 5 1) phosphorus oxide 2) phosphorus pentoxide 3) diphosphorus pentoxide C. Cl 2 O 7 1) dichlorine heptoxide 2) dichlorine oxide 3) chlorine heptoxide 8 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Solution Select the correct name for each compound. A. B. C. 9 Si. Cl

Solution Select the correct name for each compound. A. B. C. 9 Si. Cl 4 P 2 O 5 Cl 2 O 7 3) silicon tetrachloride 3) diphosphorus pentoxide 1) dichlorine heptoxide Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Learning Check Write the name of each covalent compound: 10 CO ___________ CO 2

Learning Check Write the name of each covalent compound: 10 CO ___________ CO 2 ___________ PCl 3 ___________ CCl 4 ___________ N 2 O ___________ Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Solution Write the name of each covalent compound: CO carbon monoxide CO 2 carbon

Solution Write the name of each covalent compound: CO carbon monoxide CO 2 carbon dioxide PCl 3 phosphorus trichloride CCl 4 carbon tetrachloride N 2 O dinitrogen monoxide http: //www. nbclearn. com/portal/site/learn/chemistry-now/molecule-profiles 11 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Guide to Writing Formulas Example: Write the formula for carbon disulfide. STEP 1 Write

Guide to Writing Formulas Example: Write the formula for carbon disulfide. STEP 1 Write the symbols in the order of the elements in the name. C S STEP 2 Write any prefixes as subscripts. No prefix for carbon means one(1) C. The prefix di for sulfur means two(2) S. formula: CS 2 12 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Learning Check Write the correct formula for each of the following: A. phosphorus pentachloride

Learning Check Write the correct formula for each of the following: A. phosphorus pentachloride B. dinitrogen trioxide C. sulfur hexafluoride 13 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Solution Write the correct formula for each of the following: A. phosphorus pentachloride 1

Solution Write the correct formula for each of the following: A. phosphorus pentachloride 1 P penta = 5 Cl PCl 5 B. dinitrogen trioxide di = 2 N tri = 3 O N 2 O 3 C. sulfur hexafluoride 1 S 14 hexa = 6 F SF 6 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Learning Check Identify each compound as ionic or covalent and give its correct name.

Learning Check Identify each compound as ionic or covalent and give its correct name. A. SO 3 B. Mn. Cl 2 C. (NH 4)3 PO 4 D. Cu 2 CO 3 E. N 2 O 4 15 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Solution Identify each compound as ionic or covalent and give its correct name. A.

Solution Identify each compound as ionic or covalent and give its correct name. A. SO 3 covalent; sulfur trioxide B. Mn. Cl 2 ionic; manganese(II) chloride C. (NH 4)3 PO 3 ionic; ammonium phosphite D. Cu 2 CO 3 ionic; copper(I) carbonate E. N 2 O 4 covalent; dinitrogen tetroxide 16 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Learning Check Identify each compound as ionic or covalent and give its correct name.

Learning Check Identify each compound as ionic or covalent and give its correct name. A. Ca 3(PO 4)2 B. Fe. Br 3 C. SCl 2 D. Cl 2 O 17 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Solution A. B. C. D. Ca 3(PO 4)2 Fe. Br 3 SCl 2 O

Solution A. B. C. D. Ca 3(PO 4)2 Fe. Br 3 SCl 2 O ionic Ca 2+ PO 43− ionic Fe 3+ Br − covalent 1 S 2 Cl covalent 2 Cl 1 O calcium phosphate iron(III) bromide sulfur dichloride dichlorine oxide http: //dhmo. org/ 18 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

H 2, A Covalent Molecule In a hydrogen (H 2) molecule, • two hydrogen

H 2, A Covalent Molecule In a hydrogen (H 2) molecule, • two hydrogen atoms share electrons to form a covalent single bond • each H atom acquires two (2) electrons • each H becomes stable like helium (He) 19 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Diatomic Elements • These elements share electrons to form diatomic, covalent molecules. 20 Basic

Diatomic Elements • These elements share electrons to form diatomic, covalent molecules. 20 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Learning Check What is the name of each of the following diatomic molecules? H

Learning Check What is the name of each of the following diatomic molecules? H 2 ___________ N 2 ________ Cl 2 ________ O 2 ________ I 2 ________ 21 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Solution What are the names of each of the following diatomic molecules? H 2

Solution What are the names of each of the following diatomic molecules? H 2 hydrogen N 2 nitrogen Cl 2 chlorine O 2 oxygen I 2 iodine 22 Basic Chemistry Copyright © 2011 Pearson Education, Inc.