Chapter 3- Water and Life

Question 1

Hydrophillic molecules

Answer 1

Charged molecules that are attracted to the partial charge of the water molecule.

Question 2

solution

Answer 2

a liquid that is a homogeneous mixture of two or more substances

Question 3

aqueous solution

Answer 3

a solution in which water is the solvent

Question 4

solute

Answer 4

a substance that is dissolved in a solution

Question 5

surface tension

Answer 5

a measure of how difficult it is to stretch or break the surface of a liquid.

Question 6

heat of vaporization

Answer 6

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

Question 7

hydronium ion

Answer 7

a water molecule that has an extra proton bound to it; H3O+, commonly represented as H+

Question 8

solvent

Answer 8

the dissolving agent of a solution. Water is the most versatile solvent known.

Question 9

molarity

Answer 9

a common measure of solute concentration, referring to the number of moles of solute per liter of solution

Question 10

Water’s four emergent properties

Answer 10

1. cohesive behavior
2. ability to moderate temp.
3. expansion upon freezing
4. versatility as a solvent

Question 11

What gives water the ability to dissolve substances with charges or partial charges?

Answer 11

Water’s partial charges

Question 12

pH scale

Answer 12

0-6 : acidic
7 : neutral
8-14: basic

Adding [H+] lowers the pH
Adding [OH-] increased the pH
Adding a BUFFER minimizes the changes in the concentration of [H+] and [OH-] maintaining a constant pH.`

Question 13

Hydrogen bonds

Answer 13

• weaker than covalent bonds
• ARE ATTRACTIONS! THEY DO NOT SHARE ELECTRONS
• important because they are numerous.

Question 14

H3O+

Answer 14

hydronium

Question 15

buffers

Answer 15

• made of weak acids or weak bases and their salts

- can absorb or give off H+, stabilizing pH