Chapter 21

Question 1

substance where solutes mix evenly with solvents

Answer 1

solution

Question 2

substance being dissolved in solution

Answer 2

solute

Question 3

substance in which solute is dissolved in solution

Answer 3

solvent

Question 4

how is the solvent determined in a liquid-liquid solution?

Answer 4

the substance of larger quantity = solvent

Question 5

give a common example of a gaseous solution

Answer 5

air (78% nitrogen, 21% oxygen, 1% other gases)

Question 6

give an example of a solid solution

Answer 6

brass (copper and zinc)

Question 7

solid solutions are also called:

Answer 7

alloys

Question 8

why does sugar dissolve in water?

Answer 8

water is polar and attracts other polar sugar particles until the mixture is even

Question 9

how do solids dissolve in solids?

Answer 9

metals are melted and mixed in liquid form, causing atoms to spread out evenly; when cooled, particles remain evenly mixed

Question 10

ways to increase the rate of dissolving:

Answer 10

stirring, increasing surface area, and increasing temperature

Question 11

why does increasing the surface area of a solute speed up the rate of dissolving?

Answer 11

because dissolving takes place at the surface; when surface area is greater, more particles of a solute interact w/ solvent particles and react more quickly

Question 12

maximum amount of solute able to dissolve in a solvent at a given temperature

Answer 12

solubility

Question 13

amount of solute actually dissolved within a substance

Answer 13

concentration

Question 14

solution containing all possible solute it can at the given temperature

Answer 14

saturated solution

Question 15

any solution that can dissolve more solute at the given temperature; has yet to reach the limit

Answer 15

unsaturated solution

Question 16

a solution containing more solute than a saturated solution of the same temperature

Answer 16

supersaturated solution

Question 17

explain how a supersaturated solution forms

Answer 17

occurs in specific substances; heated saturated solutions cool but do not lose any solute, causing instability and forming a supersaturated solution

Question 18

relative vs precise concentrations

Answer 18

relative: observed (ex. amount of lemon juice put into homemade lemonade)
precise: calculated (given percentage by volume of solute; 3x. 10% solution = 10% solute and 90% solvent)

Question 19

what do solubility curves measure?

Answer 19

solubility of a substance at different temperatures

Question 20

temperature and solubility have what kind of relationship?

Answer 20

direct

Question 21

why do soda bottles overflow when opened after being shaken?

Answer 21

• when cap is closed, pressure inside bottle > pressure outside bottle
• pressure releases when bottle is opened and carbon dioxide gas escapes rapidly

Question 22

compounds that produce solutions of ions in water

Answer 22

electrolytes

Question 23

substances that form no ions in water and do not conduct electricity

Answer 23

non-electrolytes

Question 24

process of molecular compounds dissolving in water and forming charged particles

Answer 24

ionization

Question 25

process in which positive and negative ions of an ionic solid mix w/ a solvent to form a solution

Answer 25

dissociation

Question 26

why don’t all substance dissolve in water?

Answer 26

no polar substances will not be attracted to water’s polar particles

Question 27

• often used for specific uses
• often flammable, toxic, and quickly-evaporating

Answer 27

nonpolar solvents

Question 28

why does soap work?

Answer 28

soap is versatile (has both polar and nonpolar particles) so it attracts both water and dirt