Unit 1: Water

Question 1

Hydrophilic

Answer 1

Water loving: molecules that are polar, charged or ionic.

Question 2

Hydrophobic

Answer 2

Water fearing: molecules that are nonpolar compounds

Question 3

Properties of water (3)

Answer 3

ice is less dense than water, high specific heat capacity, high heat of vaporization

Question 4

Reactant

Answer 4

the starting materials in a chemical reaction (to the left of the arrow)

Question 5

Products

Answer 5

the materials produced in a chemical reaction (to the right of the arrow)

Question 6

Arrows might show two things:

Answer 6

React to make or form

Question 7

Water generates charges because

Answer 7

oxygen is more electronegative than hydrogen

Question 8

Solvant

Answer 8

something that is capable of dissolving another (polar) substance

Question 9

Dissociation

Answer 9

atoms or groups of atoms break off from molecules and form ions

Question 10

Water molecules sticking to each other is

Answer 10

Cohesion (because of hydrogen bonding)

Question 11

Surface tension

Answer 11

the capacity of a substance to withstand rupturing when placed under tension or stress

Question 12

Adhesion

Answer 12

attraction to other charged, polar molecules

Question 13

What force allows plants to transport water from their roots to their leaves

Answer 13

Adhesion

Question 14

What happens when the heat rises as water boils

Answer 14

the water molecules’ higher kinetic energy causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas

Question 15

What happens when water freezes?

Answer 15

the water molecules form a crystalline structure maintained by hydrogen bonding (there is not enough energy to break the hydrogen bonds)

Question 16

What has the highest specific heat capacity of any liquids

Answer 16

Water

Question 17

high heat of vaporization

Answer 17

the amount of energy required to change one gram of a liquid substance to a gas

Question 18

Evaporation

Answer 18

Individual water molecules acquire enough energy from other water molecules such that some surface water molecules can escape and vaporize

Question 19

Equation to calculate pH

Answer 19

pH = -log[H+]

Question 20

[H+]

Answer 20

molar concentration of hydrogen ions

Question 21

Non-neutral pH readings result from

Answer 21

dissolving acids or bases in water

Question 22

Low concentrations of hydroxide ions OH- yields

Answer 22

a low pH number, high acidity

Question 23

Low levels of hydrogen -[H] ions result in

Answer 23

high pH, low acidity

Question 24

The pH scale ranges from

Answer 24

0 (high pH) to 14 (low pH). Anything above 7 is alkaline/basic.

Question 25

Buffers and bases are both

Answer 25

substances that resists a change in pH by readily donating OH– or taking up [H+]. Resisting change doesn’t mean neutral but just regulated.

Question 26

a substance with many polar covalent bonds will be

Answer 26

hydrophilic

Question 27

C-C,
C-H

Answer 27

non polar covalent bonds, hydrophobic

Question 28

O-H,
O-C

Answer 28

polar covalent bonds, hydrophillic

Question 29

[ ] brackets tell us

Answer 29

it is a concentration

Question 30

What kind of compounds dissolve well in water?

Answer 30

Charged, ionic, polar

Question 31

What type of bonds will maintain proteins shape and structure? (2)

Answer 31

Hydrogen and ionic

Question 32

Hydrogen bonds play a role in water molecules through

Answer 32

adhesion, cohesion and solvent properties