Structure of Ionic Solids - AP Chemistry

1. Identify the ions present in $CaBr_2$.

   $Ca^{2+}$ and $Br^{-}$. One divalent cation with two monovalent anions.

2. What is the coordination number in an ionic solid with cubic close-packed structure?

   12. Face-centered cubic packing maximizes coordination number.

3. Which type of ions form the lattice in MgO?

   $Mg^{2+}$ and $O^{2-}$. Divalent cation and anion create strong electrostatic attraction.

4. What is the coordination number in NaCl?

   6. Each $Na^+$ is surrounded by 6 $Cl^-$ ions in rock salt structure.

5. What is the coordination geometry in NaCl?

   Octahedral. Six-fold coordination creates octahedral geometry around each ion.

6. State a characteristic of ionic solids in solid-state.

   Rigid and brittle. Fixed ionic positions create inflexible crystal structure.

7. Which property of ionic solids affects their solubility in water?

   Polarity. Polar water molecules can surround and solvate ionic charges.

8. What is the effect of ionic radius on lattice energy?

   Larger radii decrease lattice energy. Greater separation weakens electrostatic attraction between ions.

9. What is the effect of temperature on the solubility of ionic solids?

   Generally increases solubility. Higher kinetic energy helps overcome lattice energy barriers.

10. What is the result of dissolving ionic solids in water?

    Formation of hydrated ions. Water molecules surround separated ions through ion-dipole interactions.

11. How does lattice energy affect solubility?

    Higher lattice energy decreases solubility. Stronger lattice forces resist dissolution in polar solvents.

12. What type of structure does KBr adopt?

    Face-centered cubic structure. Similar size ions adopt rock salt structure.

13. Which factor increases when ionic solids are heated?

    Vibrational energy of ions. Higher kinetic energy causes increased lattice vibrations.

14. Which property is common to ionic solids at room temperature?

    Non-conductive. Ions fixed in lattice positions prevent electrical conduction.

15. What is the definition of lattice energy?

    Energy required to separate one mole of an ionic solid into gaseous ions. Measures strength of ionic bonding in crystal lattice.

16. What occurs when ionic solids are subjected to stress?

    Cleavage along planes. Brittle fracture occurs along crystallographic planes of weakness.

17. What is the coordination number in KCl?

    6. Rock salt structure with octahedral coordination geometry.

18. Identify a property that is common in ionic solids.

    Brittleness. Rigid ionic arrangements fracture rather than deform under stress.

19. State the formula for calculating lattice energy.

    Lattice energy = $k \frac{Q_1Q_2}{r}$. Energy proportional to charge product, inversely proportional to distance.

20. Identify the ions in $SrCl_2$.

    $Sr^{2+}$ and $Cl^{-}$. One divalent cation with two monovalent anions.

21. Which type of solid is MgO classified as?

    Ionic solid. Contains $Mg^{2+}$ and $O^{2-}$ ions held by ionic bonds.

22. What is the primary interaction between ions in an ionic solid?

    Electrostatic attraction. Coulombic forces between positive and negative charges.

23. State a condition for ionic conductivity.

    Ions must be free to move. Requires molten state or aqueous solution for ion mobility.

24. What is the effect of ionic charge on lattice energy?

    Higher charges increase lattice energy. Lattice energy proportional to product of ionic charges.

25. Which type of ions typically form ionic solids?

    Metal cations and nonmetal anions. Electron transfer creates oppositely charged ions that attract.

26. What is the primary lattice structure of ionic solids?

    Crystal lattice. Regular three-dimensional arrangement of cations and anions.

27. What is the primary characteristic of ionic solids?

    High melting and boiling points. Strong electrostatic forces require significant energy to overcome.

28. Which structure does CsCl adopt?

    Body-centered cubic structure. Simple cubic arrangement due to similar ionic sizes.

29. Identify the ions present in Na_2O.

    $Na^{+}$ and $O^{2-}$. Two monovalent cations with one divalent anion.

30. What is the formula unit of calcium fluoride?

    CaF_2. One calcium cation with two fluoride anions.

31. What is the coordination number in LiI?

    6. Similar structure to NaCl with octahedral coordination.

32. What is the coordination number in CsCl?

    8. Each $Cs^+$ surrounded by 8 $Cl^-$ in cubic coordination.

33. What is the primary factor affecting ionic solid hardness?

    Strength of ionic bonds. Stronger ionic bonds create harder, more resistant materials.

34. Which type of structure does NaCl adopt?

    Face-centered cubic structure. Also called rock salt structure with octahedral coordination.

35. What is the effect of ion size on melting point of ionic solids?

    Smaller ions increase melting point. Smaller ions pack more tightly, requiring more energy to separate.

36. What is the empirical formula of an ionic compound with $Na^+$ and $Cl^-$?

    NaCl. Equal numbers of monovalent cations and anions.

37. Identify the primary type of bonding in ionic solids.

    Ionic bonding. Electrostatic attraction between oppositely charged ions.

38. What is the definition of an ionic solid?

    A crystalline solid composed of ions held together by electrostatic forces. Cations and anions arrange in repeating three-dimensional patterns.

39. Which ions form the lattice in Al_2O_3?

    $Al^{3+}$ and $O^{2-}$. Trivalent cation and divalent anion create very strong lattice.

Study these flashcards