Exam 1 Lecture 4

Question 0

True or false? Solid water is less dense than liquid water.

Answer 0

True

Question 1

True or False? Water has a HIGH specific heat and a LOW heat of vaporization?

Answer 1

False. High, high

Question 2

Water is a __________ solvent.

Answer 2

Good

Question 3

What is Hydrophobic?

Answer 3

“Water-fearing”

Question 4

What is Hydrophilic?

Answer 4

“Water-loving”

Question 5

Water causes __________ molecules it aggregate or assume specific shapes.

Answer 5

Hydrophobic

Question 6

The concentration (pH) of Hydrogen ions is __________ mol/L

Answer 6

10^-7 (7)

Question 7

__________ is the negative logarithm of hydrogen ion concentration of solution.

Answer 7

pH

Question 8

If the [H^+] (Hydrogen ion concentration) is 10^-9 mol/L, what is the pH?

Answer 8

9

Question 9

What is the pH of stomach acid? (Hint: very acidic!)

Answer 9

2

Question 10

If the pH is 2, what is the [H^+]?

Answer 10

10^-2 mol/L

Question 11

An __________ is a substance that dissociates in water to increase the [H^+] (lowers the pH).

Answer 11

Acid

Question 12

What is a Base?

Answer 12

A substance that has a lower [H^+] (higher pH).

Question 13

_________ are substances that reduce changes in pH.

Answer 13

Buffers

Question 14

Buffers __________ H^+ when a base is added and __________ H^+ when acid is added.

Answer 14

Release, Absorb

Question 15

In an ION, the number of __________ is always different from the number of __________.

Answer 15

Protons, Electrons