unit 1 - chapter 3 (water)

Question 1

what is polar covalent bonding?

Answer 1

unequal sharing of electron pair (partial positive & negative)

Question 2

what are the 4 properties of water?

Answer 2

cohesion of water molecules, moderation of temperature by water, ice floats, and water is the solution

Question 3

what is cohesion?

Answer 3

water sticks to itself

Question 4

what does cohesion cause?

Answer 4

surface temperature

Question 5

what is adhesion?

Answer 5

water sticks to other things

Question 6

what is heat?

Answer 6

total kinetic energy

Question 7

what is temperature?

Answer 7

average kinetic energy

Question 8

what is heat?

Answer 8

a form of energy

Question 9

what is heat measured in?

Answer 9

calories or joules

Question 10

what is specific heat?

Answer 10

amount of heat required to change temperature

Question 11

what’s in the blank?
water changes temperature more _____ than other substances

Answer 11

slowly

Question 12

what’s in the blank?
water requires a _____ input of energy to change temperature

Answer 12

greater

Question 13

what kind of specific heat does water have and what does this mean?

Answer 13

high specific heat, it can moderate temperature very well

Question 14

why does ice float?

Answer 14

it has a lower density than water

Question 15

what is a solution?

Answer 15

a uniform mixture of 2 or more substances

Question 16

what is a solvent?

Answer 16

the liquid dissolving reagent in a solution

Question 17

what is a solute?

Answer 17

the dissolved reagent in a solution

Question 18

why does salt dissolve well in water?

Answer 18

the Cl- anions and Na+ cations get surrounded by the water molecules and can’t join back unless the water disappears

Question 19

what does hydrophilic mean?

Answer 19

substances that are attracted to water

Question 20

what does hydrophobic mean?

Answer 20

substances that repel water

Question 21

what type of substances are usually hydrophilic?

Answer 21

generally ionic or polar substances

Question 22

what type of substances are usually hydrophobic?

Answer 22

non-polar and non-ionic substances (like oils)

Question 23

what is molecular weight the sum of?

Answer 23

all atomic weights

Question 24

what is molarity?

Answer 24

the # of moles of solute per liter

Question 25

what is avagadro’s number?

Answer 25

6.02 x 10^23 particles in 1 mole of substance

Question 26

what is an acidic pH?

Answer 26

0-7

Question 27

what is a basic pH?

Answer 27

7-14

Question 28

what is a neutral pH?

Answer 28

7

Question 29

what’s in the blank?
_____ are more reactive than water

Answer 29

ions

Question 30

what are compounds that contribute H+?

Answer 30

acids

Question 31

what are compounds that contribute OH-?

Answer 31

bases

Question 32

what does the pH scale measure?

Answer 32

the concentration of protons

Question 33

is lower pH more acidic or more basic?

Answer 33

more acidic

Question 34

what is the equation relating pH and pOH?

Answer 34

pH + pOH = 14

Question 35

what are buffers?

Answer 35

they act as acids, bases, or both; buffers minimize changes in pH

Question 36

what’s in the blank?
buffers are _____ ionizing

Answer 36

weakly

Question 37

what is an important buffer in vertebrate blood?

Answer 37

bicarbonate

Question 38

how do buffers minimize changes in pH?

Answer 38

they absorb protons

Question 39

what is an example of an ecological effect of pH?

Answer 39

acid precipitation