Chapter 2 cont. (water & its properties)

Question 1

Atoms share the electrons unequally

Answer 1

Polar Covalent Bond

Question 2

Atoms share electrons equally

Answer 2

Nonpolar Covalent Bonds

Question 3

Electrons are ___ between O and H, which is a ____ bond

Answer 3

Shared, covalent

Question 4

Why is water polar covalent?

Answer 4

Oxygen is more electronegative, obtaining a partial negative charge.

Hydrogen is less electronegative, obtain a partial positive charge

Question 5

Electropositive hydrogen from one polar molecule is attracted to an electronegative atom

Answer 5

Hydrogen bonds

Question 6

Amount of heat that must be absorbed or lost for 1 gram of that substance to be changed by 1 degree Celsius

Answer 6

specific heat

Question 7

Does water have a high or a low specific heat?

Answer 7

high// this permits life

Question 8

Heat is (absorbed/released) when hydrogen bonds break?

Answer 8

absorbed

Question 9

Heat is (absorbed/released) when hydrogen bonds form?

Answer 9

released

Question 10

The state of water in a continuous formation of hydrogen bonds forming, breaking, and forming again

Answer 10

Water as a liquid

Question 11

Water state when:

Temperature drops, causing a decrease in H-bond breakage

(less heat is absorbed, more heat is released)

Answer 11

Solid (ice)

Question 12

Water state when:

H-bonds are continuously being formed, broken, and formed again

Answer 12

Liquid (water)

Question 13

Water state when:

An increase in temperature causes an increase in bond breakage

(More heat is being absorbed)

Answer 13

Gas (water vapor)

Question 14

State change from Ice to water:

Answer 14

Input of energy/ increased H-bond breakage

Question 15

Change state from water vapor to water

Answer 15

Release of energy/ less hydrogen bond breakage, more hydrogen bonds form

Question 16

What temperature does water freeze at?

Answer 16

0 degrees Celsius

Question 17

Ice has a (lower/higher) density than liquid water

Answer 17

lower

Question 18

Water molecules are attracted to other water molecules and stick to each other via hydrogen bonding

Answer 18

Cohesion

Question 19

The measure of attraction between molecules at the surface of a liquid

Answer 19

Surface tension

Question 20

Water molecules are attracted to other polar molecules and stick to these molecules via hydrogen bonding

Answer 20

Adhesion

Question 21

Substance that is dissolved in a liquid

Answer 21

Solute

Question 22

The liquid that the substance dissolves in

Answer 22

Solvent

Question 23

When a solute is dissolved in a solvent

Answer 23

Solution

Question 24

Which type of molecules dissolve easily in water?

Answer 24

Ions (anion and cation) and polar molecules

Question 25

* “water-loving” interactions * dissolve in water * often polar or ionic * like dissolves in like

Answer 25

Hydrophilic Interactions

Question 26

* “water-fearing” interactions * Insoluble in water * non-polar, no charge

Answer 26

Hydrophobic Interactions

Question 27

Molecules that contain both hydrophilic and hydrophobic regions

Answer 27

Ampipathic molecules

Question 28

When does a chemical reaction occur?

Answer 28

* 2 or more elements or compounds combine * 1 compound breaks down into 2 or more molecules * Electrons are added or removed from atom

Question 29

When H shifts from one water molecule to another, leaving behind a hydroxide ion (OH-) and forming a hydronium ion (H3O+)

Answer 29

Ionization

Question 30

Cohesion

Answer 30

Water molecules are attracted to other water molecules and stick to each other via hydrogen bonding

Question 31

Surface tension

Answer 31

The measure of attraction between molecules at the surface of a liquid

Question 32

Adhesion

Answer 32

Water molecules are attracted to other polar molecules and stick to these molecules via hydrogen bonding

Question 33

Solute

Answer 33

Substance that is dissolved in a liquid

Question 34

Solvent

Answer 34

The liquid that the substance dissolves in

Question 35

Solution

Answer 35

When a solute is dissolved in a solvent

Question 36

Hydrophilic Interactions

Answer 36

* “water-loving” interactions * dissolve in water * often polar or ionic * like dissolves in like

Question 37

Hydrophobic Interactions

Answer 37

* “water-fearing” interactions * Insoluble in water * non-polar, no charge

Question 38

Ampipathic molecules

Answer 38

Molecules that contain both hydrophilic and hydrophobic regions

Question 39

Ionization

Answer 39

When H shifts from one water molecule to another, leaving behind a hydroxide ion (OH-) and forming a hydronium ion (H3O+)

Question 40

Polar Covalent Bond

Answer 40

Atoms share the electrons **unequally**

Question 41

Nonpolar Covalent Bonds

Answer 41

Atoms share electrons **equally**

Question 42

Hydrogen bonds

Answer 42

Electropositive hydrogen from one polar molecule is attracted to an electronegative atom

Question 43

specific heat

Answer 43

Amount of heat that must be absorbed or lost for 1 gram of that substance to be changed by 1 degree Celsius

Question 44

Scale used to describe the concentration of H+ and OH-

Answer 44

pH scale

Question 45

Increased amount of H+/ H+ *donors*

Answer 45

Acids

Question 46

Lowered amount of H+/ alkaline/ H+ *acceptors*

Answer 46

Bases

Question 47

Pair of substances that minimize pH fluctuations in the fluids of living organisms/ Work to keep H+ constance and within acceptable range

Answer 47

Buffers

Question 48

Example of an acid buffer: | (can donate hydrogen ions)

Answer 48

Carbonic acid (H2CO3)

Question 49

Example of base buffer: | (can *accept* hydrogen ions)

Answer 49

Bicarbonate ion (HCO3-)

Question 50

pH scale

Answer 50

Scale used to describe the concentration of H+ and OH-

Question 51

Acids

Answer 51

Increased amount of H+/ H+ *donors*

Question 52

Bases

Answer 52

Lowered amount of H+/ alkaline/ H+ *acceptors*

Question 53

Buffers

Answer 53

Pair of substances that minimize pH fluctuations in the fluids of living organisms/ Work to keep H+ constance and within acceptable range