Biochemistry Chapter 3- AP Bio Part 2

Question 0

What happens when these molecules move fast enough

Answer 0

The depart the liquid and enter the air as gas

Question 1

Why do molecules of any liquid stay close to one another

Answer 1

They are attracted to one another

Question 2

Vaporization (evaporation)

Answer 2

The transformation from a liquid to a gas

Question 3

Temperature

Answer 3

Average kinetic energy of molecules

Question 4

Heat of vaporization

Answer 4

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

Question 5

Water also has a high what type of other heat

Answer 5

Heat of vaporization

Question 6

What must be broken before vaporization

Answer 6

Hydrogen bonds

Question 7

How does a high heat of vaporization occur in biology

Answer 7

Helps moderate earth’s climate

Question 8

Evaporative cooling

Answer 8

As a liquid evaporates, the surface of the liquid that remains behind cools down

Question 9

How come water expands at 0°C

Answer 9

Water begins to freeze because molecules are moving too slowly to break hydrogen bonds, and molecules become locked in a crystalline lattice, each molecule is hydrogen bonded to 4 partners, so molecules are kept at “arms length”

Question 10

Where does water reach its greatest density

Answer 10

4 °C

Question 11

What does floating ice do for liquid water

Answer 11

Insulates the liquid water below, allow life to exist below the frozen surface

Question 12

Solution

Answer 12

A completely homogenous mixture of 2 or more substances

Question 13

Solvent

Answer 13

The dissolving agent of a solution

Question 14

Solute

Answer 14

The substance that is dissolved

Question 15

Aqueous solution

Answer 15

The one in which the solute is dissolved in water, water is the solvent

Question 16

Hydrogen shell

Answer 16

The sphere of water molecules around each dissolved ion

Question 17

A compound does not have to be ________ to dissolve in water

Answer 17

Ionic

Question 18

Hydrophilic

Answer 18

Any substance that has an affinity for water

Question 19

Hydrophobic

Answer 19

Substances that are nonionic and Nonpolar

Question 20

Most chemical reactions in organisms involve

Answer 20

Solutes dissolved in water

Question 21

Molecular mass

Answer 21

The sum of all the masses in a molecule

Question 22

Mole (mol)

Answer 22

Represents an exact number of objects : 6.02 x 10^23 ————>avogadros number

Question 23

Molarity

Answer 23

The number of moles of solute per lot of solution-the unit of concentration most commonly used by biologists for aqueous solutions