Electrolytes, Dissociation, and Physical Properties

What is an electrolyte?

A substance that breaks up into ions in water and conducts electricity.

What terms are used for breaking into ions in water?

Ionization or dissociation.

What is a nonelectrolyte?

A substance that does not break into ions in water and does not conduct electricity.

What is a strong electrolyte?

An electrolyte that breaks up essentially 100% into ions; NaCl is the slide example.

What is a weak electrolyte?

An electrolyte that only breaks up poorly, so some particles remain intact.

What happens when NaCl dissolves in water?

 It dissociates into Na⁺(aq) and Cl⁻(aq).

Write the dissociation of sodium chloride.

 NaCl(s) → Na⁺(aq) + Cl⁻(aq).

What happens to most molecular substances when they dissolve in water?

They remain intact rather than dissociating into ions.

What important molecular exception can form ions in water?

Acids; acids as molecular compounds that ionize in water.

Why do ionic compounds generally require high temperatures to melt?

Strong electrostatic forces in the ionic lattice hold the particles together.

How do ionic and molecular solids compare in hardness?

Ionic solids are typically hard and brittle; molecular solids are typically softer.

How do molecular and ionic melting and boiling points generally compare?

Ionic compounds have very high melting/boiling points; molecular compounds have lower ones.

How do molecular and ionic densities generally compare?

Ionic compounds are shown as higher density; molecular compounds as lower density.

How do ionic compounds conduct electricity?

The slide says conductivity is good when the ionic compound is molten; aqueous electrolytes can also conduct.

How do molecular compounds conduct electricity in pure form?

Poorly.