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Flashcards in Chapter 3 Deck (42):
1

What is the main reason the earth is habitable?

Abundance of water

2

The water molecule is a ______ molecule

polar

3

Cohesion

Water molecules hold together by hydrogen bonds

4

Adhesion

Attraction of different substances

5

What are water's properties that facilitate an environment for life?

-Cohesive behavior
-Ability to moderate temperature
-Expansion upon freezing
-Versatility as a solvent

6

Surface tension is related to which property of water?

Cohesion

7

Because of its high specific heat capacity, water _______ from ______ and ________ to _________

-absorbs heat from warmer air
-releases stored heat to cooler air

8

Kinetic energy

The energy of motion

9

How do atoms and molecules have kinetic energy?

Atoms are always moving

10

Faster moving atoms = more _____

kinetic energy

11

Total kinetic energy due to movement of atoms is _____

heat

12

Because of kinetic energy, head depends partially on _____

volume

13

Coffee has >______ than a pool, but a pool has >_____

temperature
heat

14

Calorie

Amount of heat required to raise the temperature of 1g of water by 1 degree

15

Specific heat

Amount of heat that must be absorbed or lost for 1g of that substance to change temperature by 1 Celsius

16

Specific heat of water

1 cal/g/C

17

Specific heat can also be described as...

How well a substance resists temperature change when absorbing/releasing heat

18

Heat is absorbed when ________, and released when hydrogen bonds _____

-hydrogen bonds break
-hydrogen bonds form

19

Why is specific heat good for life on earth?

Minimizes temperature fluctuations to limits that permit life

20

Evaporation

Transformation from liquid to gas

21

Heat of vaporization

Heat a liquid must absorb for 1 g to be converted to gas

22

Evaporative cooling

Liquid evaporates, cooling surface

23

Why does ice float in water?

Hydrogen bonds are more ordered, making ice less dense

24

Why does ice have less kinetic energy?

Atoms more ordered to cause less movement

25

What would happen if ice sank?

All bodies of water would eventually freeze solid

26

Solution

Mixture of 2+ substances

27

Solvent

Dissolving agent of solution

28

Solute

Substance that is dissolved

29

Aqueous solution

Solution in which water is the solvent

30

Hydration shell

Sphere of water molecules around dissolved ions from ionic compounds

31

Why is water a versatile solvent?

Its polarity allows it to form hydrogen bonds easily

32

Apart from ionic compounds, water can also dissolve compounds of __________

nonionic polar molecules

33

A large polar molecule like protein can dissolve in water if it has what?

Ionic and polar regions

34

Hydrophilic

Has an affinity for water

35

Hydrophobic

Does not have an affinity for water

36

Oil molecules are (hydrophobic/hydrophilic) because...

Hydrophobic because they have relatively nonpolar bonds

37

Colloid

Stable suspension of fine particles in liquid

38

What do chemical reactions depend on? Therefore, this depends on...

Collisions of molecules and therefore on the concentration of solutes in an aqueous solution

39

Molarity

Number of moles of solute per liter of solution

40

When hydrogen shifts atoms in hydrogen bond, what happens?

-Hydrogen atom leaves electron behind and transferred only as hydrogen ion
-Molecule w/ extra proton is hydronium ion
-Molecule w/ lost proton is hydroxide ion

41

A _____ increases the H+ concentration of a solution, while a _______ reduces the H+ concentration

-acid
-base

42

Buffers

Substances that minimize changes in concentration