3: Water And Life

Question 1

Aqueous solution

Answer 1

A solution in which H2O is the solvent

Question 2

Polar molecule

Answer 2

A molecule (such as H2O? With an uneven distribution of charges in different regions of the molecule

Question 3

Hydrogen bond

Answer 3

A a weak chemical bond that’s formed when the slightly + H atom of a polar covalent bond in 1 molecule is attracted to the slightly - atom of a polar covalent bond in another molecule (or in another region of the same molecule)

Question 4

Cohesion

Answer 4

The linking together of like molecules, often by hydrogen bonds

Question 5

Adhesion

Answer 5

The clinging of one substance to another, such as H2O to a plant cell walls by means of H bonds

Question 6

Surface tension

Answer 6

A measure of how difficult it is to break the surface of a liquid. H2O has a high _______ because of the H bonding of surface molecules

Question 7

Heat

Answer 7

Thermal energy in transfer from one body of matter to another

Question 8

Kinetic energy

Answer 8

Energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter

Question 9

Temperature

Answer 9

A measure in degrees of the average kinetic energy (thermal energy) of the atoms &smile clues in a body of matter

Question 10

Specific heat

Answer 10

The amount of heat that must be absorbed or lost for 1 g of a substance to change its temp by 1 degree C

Question 11

Heat of vaporization

Answer 11

The quantity of heat a liquid must absorb for 1 g of it to be converted from liquid to gaseous state

Question 12

Evaporative cooling

Answer 12

The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to gaseous state

Question 13

Solution

Answer 13

A liquid that’s a homogeneous mixture of two or more substances

Question 14

Solvent

Answer 14

Dissolving agent of a solution. Water is the most versatile substance known.

Question 15

Solute

Answer 15

A substance that is dissolved in a solution

Question 16

Hydration shell

Answer 16

Sphere of H2O molecules around a dissolved ion

Question 17

Hydrophilic

Answer 17

Having an affinity for H2O

Question 18

Hydrophobic

Answer 18

Having no affinity for H2O, tending to coalesce & form droplets in H2O

Question 19

Molarity

Answer 19

A common measure of solute concentration, referring to the # of miles of solute per liter of solution

Question 20

Mole

Answer 20

of grams of a substance that equals it’s molecular/atomic mass in daltons. A _____ contains avagadro’s # of the molecules/atoms in question

Question 21

Avagadro’s number

Answer 21

6.02 x 10^23

Question 22

Molecular mass

Answer 22

The sum of the masses of all the atoms in a molecule

Question 23

pH

Answer 23

A measure of the hydrogen ion concentration equal to -log[H+] and raging in value from 0-14

Question 24

Neutral

Answer 24

[H+]=[OH-]

Between acidic and basic

Question 25

Acid

Answer 25

Substance that when dissolved in H2O will raise [H+] and lower pH [H+]>[OH-]

Question 26

Base

Answer 26

Substance that when dissolved in H2O with lower [H+] raise pH
[H+]

Question 27

Buffer

Answer 27

Solution that contains a weak acid and its corresponding base. A _____ minimizes changes in pH when acids or bases are added to the solution

Question 28

Acid rain

Answer 28

Factory smoke contains sulfates and nitrates and then falls in _______ (pH