chem. activity : 6.3

What type of bonds are present in an ionic compound that contains a polyatomic ion?

Covalent bonds are inside the polyatomic ion, but the ionic compound is ionically bonded.

The lattice energy of compound A is greater in magnitude than that of compound B. What can be concluded from this fact?

It will be more difficult to break bonds in compound A than those in compound B

Arrange the ionic bonds listed below in order of increasing strength from weakest to strongest. Ionic Bond Lattice Energy (kJ/mol) NaCl -787 CaO -3384 KCl -715 MgO -3760 LiCl -861

KCI NaCI LiCI CaO MgO

What type of energy best represents the strength of an ionic bond?

Lattice energy

The notation for sodium chloride, NaCl, stands for one

formula unit

Describe the force that holds two ions together in an ionic bond.

in ionic bonds one atom is positively charged (the atom that gives its electrons), and the other atom is negatively charged (the atom that receives the electrons); therefore, it is the opposite charge of the ions that attracts them to one another and holds them together.

Compared with the neutral atoms involved in the formation of an ionic compound, the crystal lattice that results is

lower in potential energy

In a crystal of an ionic compound, each cation is surrounded by a number of

negative ions

The forces of attraction between molecules in a molecular compound are generally

weaker than the attractive forces among formula units in ionic bonding.