Ionic Compound A compound made up of one

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Ionic Compound • A compound made up of one or more positive metal ions

Ionic Compound • A compound made up of one or more positive metal ions (cations) and one or more negative non-metal ions (anions) • Most ionic compounds have: • High melting points • are hard and brittle • Form electrolytes (conduct electricity) when dissolved in water to form solutions

Formation of Sodium Chloride

Formation of Sodium Chloride

Chemical Formula of an Ionic Compound • Step 1: Write the symbols of the

Chemical Formula of an Ionic Compound • Step 1: Write the symbols of the elements, with the metal on the left-hand side and the non-metal on the right-hand side. Mg Cl • Step 2: Add the ionic charge of each ion above the symbol +2 -1 Mg Cl

 • Step 3: Determine the number of ions required to bring the charge

• Step 3: Determine the number of ions required to bring the charge to zero. 1(+2) + 2(-1) = 0 Mg O • Step 4: Write the chemical formula using the (red) coefficients in front of each bracket as subscripts Mg 1 Cl 2 Note: Do not write the subscript “ 1” The chemical formula for magnesium chloride is Mg. Cl 2

Crisscross Method • Step 1: Write the symbols of the elements and their ionic

Crisscross Method • Step 1: Write the symbols of the elements and their ionic charges Mg 2+ Cl • Step 2: Crisscross the numbers of the ionic charges so that they now become subscripts Mg 2+ Cl. Mg. Cl 2

Considering Multiple Ionic Charges • Write the chemical name of Cu. Br 2. Note

Considering Multiple Ionic Charges • Write the chemical name of Cu. Br 2. Note that copper could have either of two ionic charges (+1 or +2). • Each bromide ion has a charge of -1, so the total charge of bromide ions is 2(-1). • The ionic charge of copper in this compound is +2 • Roman numerals are included ONLY if the metal has more than one ionic charge. • The name of Cu. Br 2 is copper (II) bromide

MOLECULAR COMPOUNDS Inhaling nitrous oxide, N 2 O , helps dental patients relax Nitrogen

MOLECULAR COMPOUNDS Inhaling nitrous oxide, N 2 O , helps dental patients relax Nitrogen dioxide, NO 2 , is the gas responsible for the reddish-brown colour of smog

Most of the chemicals we encounter are molecular compounds, including: sugar water Acetylsalicylic acid,

Most of the chemicals we encounter are molecular compounds, including: sugar water Acetylsalicylic acid, or Aspirin

Soft Drinks Sugar C 12 H 22 O 11 Water H 2 O Carbon

Soft Drinks Sugar C 12 H 22 O 11 Water H 2 O Carbon Dioxide CO 2

Living Organisms • Make thousands of different kinds of molecular compounds • Sugars, fats,

Living Organisms • Make thousands of different kinds of molecular compounds • Sugars, fats, and proteins are all molecular compounds • Some of them are very large, containing thousands of atoms in a single molecule

Molecular Compounds • The majority of all known compounds are molecular • Molecules consist

Molecular Compounds • The majority of all known compounds are molecular • Molecules consist of two or more non-metal atoms joined by a covalent bond • A COVALENT BOND forms when atoms share electrons • The chemical formula gives the exact numbers of atoms in each molecule • Diatomic molecules consist of only two atoms of either the same or different elements

Ionic Bond vs Covalent Bond An Ionic bond is the simultaneous strong attraction of

Ionic Bond vs Covalent Bond An Ionic bond is the simultaneous strong attraction of positive ions and negative ions A covalent bond results from the sharing of outer electrons between non-metal atoms

Naming Molecular Compounds • Prefixes indicate how many atoms of each element are present

Naming Molecular Compounds • Prefixes indicate how many atoms of each element are present (for example, dinitrogen pentoxide, N 2 O 5) • If there is only one atom of the first element, the prefix “mono” is omitted • The name of the last element ends in “ide. ” Prefix Mon(o)- Number of Atoms 1 Di- 2 Tri- 3 Tetra- 4 Penta- 5

Writing Formulas of Molecular Compounds • Prefixes in the name become the subscripts in

Writing Formulas of Molecular Compounds • Prefixes in the name become the subscripts in the formula Sulfur dioxide SO 2

Hotdogs contain many chemical additives Sodium nitrite Preservative and colour enhancer Sodium phosphate Binding

Hotdogs contain many chemical additives Sodium nitrite Preservative and colour enhancer Sodium phosphate Binding agent Sodium erythrobate Preservative

Nitrites are not all bad news. . . • Research suggests that sodium nitrite

Nitrites are not all bad news. . . • Research suggests that sodium nitrite may help protect heart tissue after a heart attack or heart transplant • Nitrites and nitrates occur naturally in soil and are important plant nutrients

Polyatomic Ions • A polyatomic ion is an ion that consists of a stable

Polyatomic Ions • A polyatomic ion is an ion that consists of a stable group of several atoms acting together as a single charged particle. • The ionic charge of a polyatomic ion is shared over the entire ion rather than being on just one atom 3 - Phosphate Ion

Formulas and Charges of Common Polyatomic Ions Name of Polyatomic Ion Nitrate ion Nitrite

Formulas and Charges of Common Polyatomic Ions Name of Polyatomic Ion Nitrate ion Nitrite ion Hydroxide Carbonate Sulfate Phosphate Ammonium Ion Formula Ionic Charge NO 3 NO 2 OHCO 32 SO 42 PO 43 NH 4+ -1 -1 -1 -2 -2 -3 +1

Naming Compounds involving Polyatomic Ions Write the name of the compound Fe(NO 3)3 Step

Naming Compounds involving Polyatomic Ions Write the name of the compound Fe(NO 3)3 Step 1: Write the name of the metal and check whether it has more than one possible ionic charge. Iron has two possible charges (+2 and +3) Step 2: Determine the ionic charge of the metal. Fe(NO 3)3 x + 3(-1) = 0 x=+3 Step 3: Write the name of the compound with the Roman numeral if necessary. The name of Fe(NO 3)3 is iron (III) nitrate.

Writing Formulas for Compounds Containing Polyatomic Ions What is the chemical formula of copper

Writing Formulas for Compounds Containing Polyatomic Ions What is the chemical formula of copper (II) nitrate? Step 1: Write the symbol of each ion, with its charge. Cu 2+ (NO 3)Step 2: Crisscross the numbers of the ionic charges so that they become subscripts. Cu 2+ (NO 3)Step 3: Write any necessary subscripts after the brackets around each ion. The formula of copper (II) nitrate is Cu(NO 3)2

What is the most common ending for the name of. . A) a polyatomic

What is the most common ending for the name of. . A) a polyatomic anion? “ –ate” (nitrate, chlorate, sulfate, phosphate) B) an anion made up of only one element? “ –ide” (nitride, chloride, sulfide, phosphide)