Chapter 5 Solutions

Question 1

Solution

Answer 1

Homogenous mixture of substances composed of at least one solute and one solvent. Uniform at the molecular level.

Question 2

Heterogeneous Mixture

Answer 2

Contains particles large enough to block or scatter light waves. Opaque or translucent in appearence.

Question 3

Homogenous Mixture

Answer 3

A mixture in which the proportion of each chemical in the sample remains the same, no matter how small the sample is.

Question 4

Aqueous solution

Answer 4

Water is the solvent

Question 5

Electrolyte

Answer 5

Compounds whose aqueous solutions conduct electricity

Question 6

Nonelectrolyte

Answer 6

Compounds whose aqueous solutions do not conduct electricity

Question 7

Dissociation

Answer 7

The separation of ions that occurs when an ionic compound dissolves in water

Question 8

Ionization

Answer 8

The process by which a neutral atom or molecule is converted into an ion

Question 9

Breaking existing bonds

Answer 9

Uses energy

Question 10

Forming new bonds

Answer 10

Releases energy

Question 11

What did Svante Arrhenius first explain

Answer 11

Electrolytes. He focused on why some aqueous solutions conduct electricity, but others do not.

Question 12

What did Arrhenius propose in 1887?

Answer 12

When particles of a substance dissolve, they separate from each other and disperse into the solution. Nonelectrolytes disperse as electrically neutral particles. When ionic compounds dissolve, the individual ions separate. The charged particles explain the conductivity of the solutions.

Question 13

What bonds may be broken in the dissociation of an ionic compound?

Answer 13

• Ionic bonds in a solid
• intermolecular forces between water molecules
  The breaking of these bonds absorbs energy

Question 14

What bonds may form in the dissociation of an ionic compound?

Answer 14

• electrostatic forces between ions and water molecules

The bond formed releases energy

Question 15

Strong acids, three examples

Answer 15

Acids that are very good conductors. Sulfuric acid, nitric acid, hydrochloric acid are examples of very strong acids that are almost completely ionized when in solution.

Question 16

Weak acids

Answer 16

Acids with low conductivity. Most common acids, such as acetic acid, are weak.

Question 17

Solubility of nonpolar molecular compounds

Answer 17

Generally do not dissolve in water

Question 18

Solubility of polar molecular compounds

Answer 18

May be Slightly soluble in water

Question 19

Solubility of polar molecular compounds with hydrogen bonding

Answer 19

These types of bonds are most likely to be very soluble in water

Question 20

Examples of molecular compounds with high solubility

Answer 20

• ammonia, NH3(g)
• hydrogen peroxide, H2O2(l)
• methanol, CH3OH(l)
• ethanol, C2H5OH(l)
• glucose, C6H12O6(s)
• sucrose, C12H22O11(s)

Question 21

Examples of molecular compounds with low solubility

Answer 21

• methane, CH4(g)
• propane, C3H8(g)
• octane, C8H18(l)

Question 22

Concentration

Answer 22

Ratio that compares the volume of solute to the quantity of solution.
Concentration = quantity of solute/ quantity of solution

Question 23

Percentage by volume

Answer 23

Volume of a solute (mL) dissolved in every 100mL of a solution. expressed as %V/V
c = V solute/ V solution x 100%

Question 24

Percentage weight (mass) by volume

Answer 24

Mass of a substance (g) dissolved in every 100mL of solution. Expressed as %W/V
c = m solute/ V solution x 100%

Question 25

Percentage weight by weight (mass)

Answer 25

The mass of a solute (g) over the mass of a solution (g) times 100%. Expressed as %W/W
c = m solute/ m solution x 100%

Question 26

Solubility of solids in water

Answer 26

Usually more soluble at higher temperatures.