Presentation on theme: "Ionic Bonds And Ionic Compounds"— Presentation transcript:
1Ionic Bonds And Ionic Compounds Section 7.2Ionic BondsAndIonic Compounds
2Formation of an Ionic Bond CompoundA chemical combination of two or more different elementsBinary compounds when there are exactly two different elements
3Formation Na + Cl Na+ + Cl- + energy P. 210 shows chemical reactions that form ionic bonds and release energySodium and chlorine gas produce a white crystalline solidNa + Cl Na+ + Cl- + energyThis is called a chemical equation.
4What Happened? + Sodium transferred one valence electron to chlorine. [Na]+ + [Cl]- + energy+This is the electron-dot structures
5Types of Ionic Compounds Electrostatic force holds the charged atoms together is the ionic bond.Metal and non-metal ionic bond are called oxides.Most other ionic compounds are called salts.
6Names Sodium + Chlorine forms sodium chloride Sodium is a metal Chlorine is a non-metalChange chlorine to chloride in the name of the compound
7p. 210 bRibbon of magnesium metal burns in air, it forms the ionic compound magnesium oxide.Magnesium is a metalOxygen is a non-metalNotice the name, oxygen became oxide.Is this a binary ionic compound?
8Questions Explain how an ionic compound forms from these elements sodium and nitrogenlithium and oxygenstrontium and flourinealuminum and sulfur
9Challenge Question11. Explain how elements in group 1 and group 15 combine to form an ionic compound.
10Properties of Ionic Compounds Physical structureRatio of positive and negative ionsIons are packed into repeating patternBalance the forces of attraction and repulsion between ions* No single unit of Na and Cl exists, there are many Na+ and Cl- ions in a 1 to 1 ratio.
13Crystal Lattice Three dimensional geometric arrangement of particles Each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ionsThe number of ions and the ratio determine the size and shape
14Examples Minerals More than 1/3 of all known minerals are silicates HalidesBoratesCarbonatesWhat elements do you think are in these?
15Physical Properties Melting point Boiling point Hardness Depends on how strong the ionic attraction isIonic crystals are hard, rigid, brittle solids, hard to break apart – high melting and boiling pointsConduct electricitySolids: ions are locked into place, cannot conduct electricityMelt or dissolve solids into solutionsElectrolytes are solutions that conduct electricity and important to humans
16Energy Endothermic Energy is absorbed Exothermic Energy is released Formation of ionic compoundsForms more stable system so lower energy state, release energy
17Math / GraphMake a scatterplot of Interionic Distance and Lattice EnergyTitle_______________(kJ/mol)(μm)
18Lattice Energy and Interionic Distance Ionic Radius: the sum of the radii of each ionLi+: 76 μmF-: 133 μmCl-: 181 μmI-: 220 μmFindLiF, LiCl, LiILattice EnergyLiF: kJ/molLiCl: kJ/molLiI: kJ/molPlot each ionic compoundUse a different color for each point and label
19RelationshipUse your graph to describe the relationship between the interionic distance and lattice energy.Fill in the blanks:As interionic distance ________, lattice energy ___________.
20Lattice EnergyEnergy required to separate 1 mol of the ions in an ionic compoundThe greater the lattice energy, the stronger the force of attraction ( harder to separate)
21Predict Use your graph to estimate the lattice energy for LiBr. The ionic radius of Br- is 196 μm.
22Patterns in Lattice Enery Make a line graph of compound versus lattice energy (kJ/mol)Make each set of compoundsa different color, 4 colorsLi set – blueNa set – redK set – greenRb set - orange
23Compound Lattice Energy LiF LiCl LiBr LiI -1032 -852 -815 -761 NaF NaClNaBrNaI-926-786-752-702KFKClKBrKI-813-717-689-649Make each set of compounds a different colorLi set – blueNa set – redK set – greenWrite a few sentences to describe any pattern you see.
24Prediction Predict the shape of the graph of the lattice energies of RbF, RbCl, RbBr, RbI
25Add to Graph in OrangeAdd the Rb___ compounds to your graph in orange to verify your prediction.RbF 774
26SummaryIonic compounds contain ionic bonds formed by the attraction of oppositely charged ions.Ions in a ionic compound are arranged in repeating patterns known as a crystal lattice.Ionic compounds properties are related to ionic bond strength.
27Ionic compounds are electrolytes; they conduct an electric current in the liquid phase and in aqueous solution.Lattice energy is the energy needed to remove 1 mol of ions from its lattice.
28QuestionsExplain how an ionic compound made up of charged particles can be neutral?Describe the energy change associated with ionic bond formation, and relate it to stabillity.Identify three physical properties of ionic compounds that are associated with ionic bonds, and related them to bond strength.
29Explain how ions form bonds, and describe the structure of the resulting compound. Relate lattice energy to bond strength.Use electron configurations, orbital notations and electron dot structures to represent the formation of an ionic compound from the mental strontium and the non-metal chlorine.
30QuestionUsing the elements aluminum and oxygen, determine the formula for the ionic compound.Extension: Use Fe2+ and Fe3+ to combine with O2-Determine the formula for the ionic compounds.
31Each Student List a metal and a non-metal Exchange papers and determine the ionic compound formed between them.
32Exit TicketDetermine the ionic compound formed from Mg and Cl and explain how it was formed.Include its ratio