AP Practice Exam #2

For a given arrangement of ions, the lattice energy increases as ionic radius __________ and as ionic charge

• decreases, increases

• increases, decreases

• increases, increases

• This cannot be predicted.

• decreases, decreases

Which series of ionic compounds is correctly arranged in order of increasing lattice energy?

• MgO < CaO < SrO

• CaO < SrO < ScN

• LiCl < NaCl < NaF

• MgCl2 < NaCl < SrCl2

• RbCl < SrCl2 < MgCl2

Lattice energy is ____________.

• the energy required to convert a mole of ionic solid into its constituent ions in the gas phase

• the energy given off when gaseous ions combine to form one mole of a covalent solid

• the energy required to produce one mole of an ionic compound from its constituent elements in their standard states

• the sum of ionization energies of the components in an ionic solid

• the sum of electron affinities of the components in an ionic solid

The lattice energy of rubidium fluoride, RbF and cesium chloride, CsCl are 760KJ/Mol and 650 KJ/Mol respectively. The lattice energy of cesium flouride,CsF is expected to be,

• 600 kJ/mol

• 720 kJ/mol

• 365 kJ/mol

• 220 kJ/mol

• 820 kJ/mol

For the Born-Haber Cycle, which energy change corresponds to the electron affinity of fluorine?

• 2

• 3

• 4

• 5

• 1

For the Born-Haber Cycle, which energy change corresponds to the first ionization energy of potassium?

• 2

• 3

• 4

• 5

• 1

For the Born-Haber Cycle, which energy change corresponds to the breaking of the covalent bond?

• 2

• 3

• 4

• 5

• 6

For the Born-Haber Cycle, which energy change corresponds to the electron affinity of fluorine?

• 79.4

• 375.7

• -328.2

• -756.9

• -553.5

For the Born-Haber Cycle, which energy change corresponds to the negative lattice energy of potassium fluoride?

• 2

• 3

• 4

• 5

• 6

K_(s) + ½ Cl_2(g) → KCl_(s) ∆H = - 437 kJ/mol_rxn

The elements K and Cl react directly to form the compound KCl according to the equation above. Refer to the information above and the table below to answer the questions that follow.Which of the values of ∆H° for a process in the table is (are) less than zero (exothermic)?

• z only

• y and z only

• w, y, and z only

• w, x, y, and z

• w only