Unit 1: Chemistry of Life - Water Properties

Question 1

What do all life on earth have in common?

Answer 1

They’re all made up of atoms

Question 2

What 6 elements are abundant in living organisms?

Answer 2

Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur

Question 3

Ionic bonding

Answer 3

A bond in which electrons are transferred from one element to another

Question 4

What does ionic bonding result in?

Answer 4

Ions or charged particles

Question 5

Cations

Answer 5

Positively charged

Question 6

Anions

Answer 6

Negatively charged

Question 7

Valence electrons

Answer 7

Electrons in the outermost shell

Question 8

Covalent bonding

Answer 8

A bond that is formed when electrons electrons are shared between elements

Question 9

What does electronegativity stand for?

Answer 9

High electronegative atom

Question 10

Electronegativity

Answer 10

An atom which has a strong pull on another atom’s electrons

Question 11

What does electronegativity result in?

Answer 11

Partial charges

Question 12

Non-polar covalent bonds

Answer 12

Equal sharing of electrons

Question 13

Examples of 2 non-polar covalent bonds

Answer 13

O2, CO2

Question 14

Polar covalent bonds

Answer 14

Unequal sharing of electrons

Question 15

What happens in polar covalent bonding?

Answer 15

An electronegative atom will pull on another atom’s electrons

Question 16

What does polar covalent bonding result in?

Answer 16

Unequal charges

Question 17

Example of polar covalent bond

Answer 17

H2O

Question 18

How are electrons shifting in a water molecule?

Answer 18

Oxygen pulls on the two hydrogen atoms’ electrons

Question 19

What are the partial charges in a water molecule?

Answer 19

H is partially positive, O is partially negative

Question 20

How would you classify the bond between an H and O in a water molecule?

Answer 20

Polar covalent

Question 21

A molecule that contains S, P, O, F, or N is…

Answer 21

Polar covalent

Question 22

Why are molecules that contains S, P, O, or N polar?

Answer 22

They are highly electronegative

Question 23

A molecule that contains long hydrocarbon chains is…

Answer 23

Non-polar covalent

Question 24

Symmetrical molecules are…

Answer 24

Non-polar covalent

Question 25

Asymmetrical molecules are…

Answer 25

Polar covalent

Question 26

Polar molecules =

Answer 26

Hydrophilic

Question 27

Non-polar molecules =

Answer 27

Hydrophobic

Question 28

If there is a charge on a molecule, it is…

Answer 28

Polar covalent

Question 29

Hydrogen bonds

Answer 29

A weak attraction between a hydrogen atom and a partially negative atoms

Question 30

Hydrogen bonds can exist in between…

Answer 30

Water molecules

Question 31

The partially positive H in one molecule of water is attracted to…

Answer 31

The partially negative O in another molecule of water

Question 32

Hydrophilic

Answer 32

Mixes with water

Question 33

Hydrophobic

Answer 33

Does not mix with water

Question 34

Examples of hydrophilic molecules

Answer 34

Glucose, NaCl

Question 35

Examples of hydrophobic molecules

Answer 35

O2, CO2

Question 36

A molecule with a partial positive or negative charge is…

Answer 36

Polar covalent

Question 37

Cohesion

Answer 37

Water’s ability to stick to itself due to hydrogen bonds

Question 38

Adhesion

Answer 38

Water’s ability to stick to other polar and charged molecules

Question 39

Transpiration

Answer 39

Evaporation of water through the leaves of plants or trees

Question 40

In a tree, what does cohesion do?

Answer 40

Allows water molecules to move up the tree

Question 41

In a tree, what does adhesion do?

Answer 41

Prevents the back flow of water

Question 42

Heat capacity

Answer 42

The amount of energy it takes to change the temperature of water

Question 43

Why is heat capacity important for aquatic life?

Answer 43

It is important so there are no large temperature fluctuations

Question 44

Heat of vaporization

Answer 44

Thermoregulation

Question 45

How does heat of vaporization and thermoreguation work?

Answer 45

The body gets hot, causes sweat, sweat absorbs heat, cools down body

Question 46

What is surface tension caused by?

Answer 46

A lack of water molecules at the surface

Question 47

What happens to intermolecular forces at the surface of water?

Answer 47

Higher intermolecular forces

Question 48

What is surface tension?

Answer 48

Tendency of liquids to shrink into the minimum surface area possible

Question 49

What bond is responsible for the surface tension of water?

Answer 49

Hydrogen bonding

Question 50

How is hydrogen bonding responsible for the surface tension of water?

Answer 50

Hydrogen bonding create a cohesive force that allows water molecules to stick together

Question 51

How does the density of ice compare to the density of water?

Answer 51

Ice is less dense than water

Question 52

Why is ice floating significant?

Answer 52

If ice had a higher density and sank, living organisms would get crushed by the ice