Chapter 2 & 3 Quiz

Question 1

What is hydrogen bonding?

Answer 1

Hydrogen bonding is an intermolecular force that emerges from the polarity of water molecules.

Question 2

What are the properties of water?

Answer 2

• cohesion
• adhesion
• high surface tension
• high specific heat
• evaporative cooling

Question 3

What is cohesion?

Answer 3

Cohesion is the tendency of water molecules to stick to each other.

Question 4

What is adhesion?

Answer 4

Adhesion is the tendency of water molecules to stick to other substances

Question 5

What is polarity?

Answer 5

The partial positive charge and negative charge that a bond/molecule has when electrons are unequally shared between 2 or more atoms.

Question 6

What is specific heat?

Answer 6

The amount of thermal energy needed to raise the temperature of 1g of a substance by 1 degree.

Water has a high specific heat

Question 7

What is surface tension?

Answer 7

The tension of the surface of a liquid caused by the attraction of the particles in the surface layer.

Question 8

What is evaporative cooling?

Answer 8

Evaporated cooling is how animals keep cold during high temperatures. Evaporating water molecules pull other water molecules up with them with cohesion and take the heat with them, leaving us cooler.

Question 9

How does water’s high specific heat help life?

Answer 9

Because water has such a high specific heat, it can absorb a lot of heat without evaporating (which is useful in hot climates) and it releases the heat when it gets cooler. This way water helps temperatures stay at an equilibrium.

Question 10

What are the most common functional groups found in biological molecules?

Answer 10

Hydroxyl, methyl, carboxyl, sulfhydryl, amino, and phosphate.

Question 11

I have a nitrogen atom. I pick up positive hydrogen atoms from a solution, which means I act as a base. I help form, along with carboxyl, the amino acids.
What group am I?

Answer 11

Group name: Amino

Question 12

Amine formula

Answer 12

NH2

Question 13

Are amines polar?

Answer 13

Yes

Question 14

Are amines hydrophilic or hydrophobic?

Answer 14

Hydrophilic

Question 15

I am a hydrogen atom bonded to an oxygen atom. I help form alcohols. What am I?

Answer 15

Hydroxyl

Question 16

Hydroxyl formula

Answer 16

OH

Question 17

Is hydroxyl polar?

Answer 17

Yes

Question 18

Is hydroxyl hydrophilic or hydrophobic?

Answer 18

Hydrophilic

Question 19

One carbon with three hydrogen atoms.

Answer 19

Methyl

Question 20

Methyl formula

Answer 20

CH3

Question 21

Is methyl polar?

Answer 21

No

Question 22

Is methyl hydrophobic or hydrophilic?

Answer 22

Hydrophobic

Question 23

I contain sulfur and hydrogen.
What am I?

Answer 23

Sulfhydryl

Question 24

Is sulfhydryl polar?

Answer 24

No

Question 25

Is sulfhydryl hydrophobic or hydrophilic?

Answer 25

Hydrophobic

Question 26

Sulfhydryl formula

Answer 26

SH

Question 27

I am phosphorus atom bonded to four oxygen atoms. I am usually ionized. What am I?

Answer 27

Phosphate

Question 28

Phosphate formula

Answer 28

PO4

Question 29

Is phosphate hydrophobic or hydrophilic?

Answer 29

Hydrophilic

Question 30

Is phosphate polar?

Answer 30

No

Question 31

I act as an **acid**, which means I contribute a positive hydrogen to solutions. When I do that I become **ionized**. I am actually a **combination of two other functional groups**. What am I?

Answer 31

Carboxyl

Question 32

Carboxyl formula

Answer 32

COOH

Question 33

Is carboxyl polar?

Answer 33

Yes

Question 34

Is carboxyl hydrophobic or hydrophilic?

Answer 34

Hydrophilic