Chapter 15 - Water And Aqueous Systems

Question 0

Surface tension

Answer 0

The inward force, or pull, that tends to minimize the surface area of a liquid.

Question 1

What factor causes the high surface tension, low vapor pressure, and high boiling point of water?

Answer 1

Many unique and important properties of water, including its high surface tension, low vapor pressure, and high boiling point - result from hydrogen bonding.

Question 2

Surfactant

Answer 2

Is any substance that interferes with the hydrogen bonding between water molecules and thereby reduces surface tension.

Question 3

Vapor pressure and hydrogen bonding

Answer 3

Hydrogen bonding between water molecules also explains water’s unusually low vapor pressure.

Question 4

Boiling point and vapor pressure

Answer 4

Molecular compounds of low molar mass are usually gases or liquids with low boiling points at normal atmospheric pressure.

Question 5

How can you describe the structure of ice?

Answer 5

The structure of ice is a regular open framework of water molecules in a hexagonal arrangement.

Question 6

Aqueous solution

Answer 6

Is water that contains dissolved substances.

Question 7

Solvent

Answer 7

The dissolving medium (water).

Question 8

Solvent

Answer 8

The dissolved particles in a solution.

Question 9

What types of substances dissolve most readily in water?

Answer 9

Substances that dissolve most readily is water include ionic compounds and polar covalent compounds.

Question 10

Solvation

Answer 10

The process by which the positive and negative ions of an ionic solid become surrounded by solvent molecules.

Question 11

Electrolyte

Answer 11

A compound that conducts electric current when it is in an aqueous solution or in the molten state.

Question 12

Why are all ionic compounds electrolytes?

Answer 12

All ionic compounds are electrolytes because they dissociate into ions.

Question 13

Nonelectrolyte

Answer 13

A compound that does not conduct an electric current in either an aqueous solution or the molten state.

Question 14

Strong electrolyte

Answer 14

All or nearly all of the solute exists as ions.

Question 15

Weak electrolyte

Answer 15

Conducts an electric current poorly because only a fraction of the solute in the solution exists as ions.

Question 16

Suspension

Answer 16

A mixture from which particles settle out upon standing.

Question 17

What is the difference between a suspension and a solution?

Answer 17

A suspension differs from a solution because the particles of a suspension are much larger and do not stay suspended indefinitely.

Question 18

Colloid

Answer 18

A heterogenous mixture containing particles that range in size from 1 nm to 1000 nm.

Question 19

What distinguishes a colloid from a suspension and a solution?

Answer 19

Colloids have particles smaller that those in suspension and larger that those in solutions.