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Ionic Compounds Containing Multivalent Ions. Learning Goal: Students will name and determine the formula of multivalent compounds. Ionic Compounds Containing Transition Metals (Multivalent Compounds). The transition metals are located in groups 3-12 of the periodic table.
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Ionic Compounds Containing Multivalent Ions Learning Goal: Students will name and determine the formula of multivalent compounds
Ionic Compounds Containing Transition Metals (Multivalent Compounds) • The transition metals are located in groups 3-12 of the periodic table. • The charge on transition metal ions are not easily determined by their location on the periodic table – for reasons you will learn about in Grade 12 Chemistry. • Also, many transition metals have more than one charge (known as an oxidation state).
Eight Important Transition Metals Highlight these on the periodic table I gave you in class. The possible charges are listed in the upper left hand corner for any multivalent metals.
Naming Multivalent Ions • When naming any ion that has more than one ionic charge, you MUST include a Roman numeral in brackets following the name of the ion. • The Roman numeral is equal to the charge on the ion. Examples: • Cu2+ = copper (II) ion • Sn4+ = tin (IV) ion
Naming Multivalent Ionic Compounds • When you name an ionic compound that contains a transition metal that is multivalent YOU MUST INCLUDE THE ROMAN NUMERAL. • CuF2is NOT named copper fluoride! • Why NOT? • Naming the compound copper fluoride does not tell us whether or not the compound contains a copper (I) or copper (II) ion. • Solution: Determine the charge on the anion first! Then determine the charge the cation must be so that the overall charge of the compound is ZERO. • We know that a fluoride ion always has a charge of 1-. • There are 2 fluoride ions in CuF2 this would result in a net charge of 2- • This means that the copper had to be 2+. • Therefore the name of the compound is: copper (II) fluoride
Learning Check: Whiteboards • Name the following compounds: • SnI2 • PbF4 • CuS • CaBr2 • Mn(NO3)2 • CoPO4
Determining the Formula of Multivalent Compounds • Write the symbol for each element in the compound. • The roman numeral will tell you the charge on the metal cation. • Determine the charge on the non-metal or polyatomic anion. • Determine how many of each you will need so that the overall charge is zero.
Determining the Formula for Multivalent Compounds Watch out of “ide” vs. “ate” and “ite” endings!!!! “-ide” = simple binary ionic Any other ending = polyatomic • Example: iron (II) bromide Fe2+ Br1- Br1- The chemical formula is FeBr2 cobalt (III) nitrate Co3+ NO31- NO31- NO31- The chemical formula is Co(NO3)3
Learning Check - Whiteboards Determine the chemical formula for each of the following: • mercury (I) oxide • tin (II) nitride • manganese (IV) phosphate • chromium (III) sulfite
Covalent Compounds Learning Goal: Students will… Define covalent compounds Draw lewis dot diagram and structural diagrams for covalent compounds Name and determine the formula of covalent compounds
Agenda • Warm-up: Multivalent Compounds • Classifying Compounds • Note: Molecular Compounds • Worksheet: Naming and Determining Formula of Molecular Compounds • Whiteboard Fun!
Open Sort: Classifying Compounds • Cut out the table of compounds provided • Think: How will you classify the compounds? • Pair: Find a partner. • Share: Describe to your partner how you classified the compounds. Is there any compounds that look new to you?
What is a Covalent Compound? • A compound formed when non-metal atoms SHARE electrons. • A covalent bond forms as a result of this sharing of electrons. • WHY SHARE ELECTRONS? • By sharing valence electrons, atoms fill their outermost energy level. • Since most atoms require eight valence electrons this is known as the OCTET rule.
Valence • Example: • An oxygen atom has 6 valence electrons. • It would need to share two electrons with other atoms to fill its outer valence. • We say that the VALENCE of oxygen is two, since oxygen forms two bonds.
Forming Covalent Compounds • If you had 2 oxygen atoms, they would each need to share 2 electrons to fill their valence shell. • Since two pairs of electrons are shared between them a double bond is formed. Lone Electron Pair (unshared) Shared Pair Electrons Lewis Dot Diagram for O2
Forming Covalent Compounds • By sharing two pairs of electrons, each oxygen atom has filled their outer shell. • We can also write the Lewis Dot Diagram to show which electrons are being shared. • A straight line equals one pair of shared electrons.
Remember… • All of the following elements are found as diatomic molecules at room temperature: HOFBrINCl
Drawing Lewis Dot Diagrams of Covalent Compounds • Example: HCl • Draw the lewis dot diagram for each element. • Re-arrange the electrons so that each non-metal atom achieves stability by filling its outer valence orbit.
Try These… • Draw the Lewis Dot Diagram for the following covalent compounds. • HINT…the atom with the highest valence (can form the most bonds) goes in the middle) • CO2 • H2O • CF4
Naming Covalent Compounds • When naming covalent compounds you can distinguish them from ionic compounds because… • IONIC COMPOUNDS USUALLY BEGIN WITH A METAL! • COVALENT COMPOUNDS CONTAIN TWO NON-METALELEMENTS ONLY! • Use the following system for naming covalent compounds: (prefix if more than one) non-metal + (prefix always) non-metal “ide”
Examples: • CO • NH3 • N2O5 • IF5 carbon monoxide PREFIXES mono- 1 di- 2 tri- 3 tetra- 4 penta- 5 hexa- 6 hepta- 7 octa- 8 hexa- 9 deca- 10 nitrogen trihydride dinitrogenpentoxide Iodine pentafluoride
Determining the Formula of Covalent Compounds • Use the prefixes to determine the subscripts in the chemical formula… • chlorine dioxide • tetraphosphorustrisulfide • sulfur hexafluoride • Diphosphoruspentaoxide ClO2 P4S3 SF6 P2O5
HomeworkMolecular Compounds Worksheet & Putting It All Together