Chapter 3: Water And Life

Question 1

How much water makes up a cell?

Answer 1

About 70-95%

Question 2

Is oxygen or hydrogen more electronegative in water?

Answer 2

Oxygen is more electronegative so it gets the electrons more of the time

Question 3

What type of bond is where the electrons are shared unequally?

Answer 3

Polar covalent bond

Question 4

Define a non polar covalent bond

Answer 4

The unequal sharing of electrons due to differences in electronegativity

Question 5

Is water polar or nonpolar?

Answer 5

Polar

Question 6

Does oxygen or hydrogen have the positive charge in H2O?

Answer 6

Oxygen is slightly negative and hydrogen is slightly positive

Question 7

What is a hydrogen bond?

Answer 7

The slightly positive of one hydrogen and the slightly negative of another oxygen are held together

Question 8

How strong is a hydrogen bond compared to a covalent bond?

Answer 8

1/20

Question 9

What is cohesion?

Answer 9

Hydrogen bonds are holding the substance together

Question 10

How is cohesion used in plants with their water supply?

Answer 10

Hydrogen bonds cause water molecules leaving the veins to be pulled up through the trunk as water evaporates

Question 11

Define adhesion.

Answer 11

The clinging of one substance to another

Question 12

What does adhesion help water counter react in plants with their water supply?

Answer 12

Gravity

Question 13

What is the word for a measure of how difficult it is to stretch or breaks the surface of a liquid?

Answer 13

Surface tension

Question 14

Do atoms and molecules have potential or kinetic energy?

Answer 14

Kinetic energy

Question 15

For a given body of matter, the amount of heat is a measure of the matter’s total ______ energy due to the motion of it’s molecules.

Answer 15

Kinetic

Question 16

What is a calorie?

Answer 16

The amount of heat it takes to raise the temperature of 1 gram of water by 1 degree Celsius

Question 17

How many calories are in a kilocalorie?

Answer 17

1000

Question 18

Define specific heat

Answer 18

Amount of heat that must be absorbed or lost for 1 gram of that substance to change its temperature by 1 degree Celsius

Question 19

When heat is absorbed, it _______ hydrogen bonds.

Answer 19

Break

Question 20

When heat is released, hydrogen bonds are _______.

Answer 20

Formed

Question 21

Define heat of vaporization.

Answer 21

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

Question 22

What is the word for as a liquid evaporates, the surface of the liquid that remains behind cools down.

Answer 22

Evaporative cooling

Question 23

What is a liquid that is completely homogeneous mixture of two or more substances?

Answer 23

A solution

Question 24

Differentiate between solute and solvent.

Answer 24

Solvent is what is doing the dissolving and the substance being dissolved is the solute

Question 25

An aqueous solution is one in which _______ is the solvent.

Answer 25

Water

Question 26

Does a compound need to be ionic to dissolve in water?

Answer 26

No

Question 27

How can large molecules such as proteins dissolve in water?

Answer 27

A long as they have ionic and polar regions on their surface then they can dissolve

Question 28

Do hydrophilic or hydrophobic substances have an affinity for water? Which don't have an affinity for water?

Answer 28

Hydrophilic substances have an affinity for water and hydrophobic do not have an affinity for water

Question 29

What is a colloid?

Answer 29

These are mixtures where there is a substance that does not dissolve

Question 30

Explain the hydrogen ion, hydronium ion, and the hydroxide ion.

Answer 30

Hydrogen ion is H+, hydroxide ion is OH-, and the hydronium ion is H3O

Question 31

How do acids and bases make substances more acidic and basic?

Answer 31

Acids releases H+ and bases absorb H+