Ch. 2.2 Properties of Water

Question 1

Properties of water?

Answer 1

Water is polar, water resists temperature changes, and water expands when it freezes.

Question 2

**Polar molecule =

Answer 2

A molecule with an unequal distribution of charge.

Question 3

**Polar molecules have?

Answer 3

A positive and a negative end.

Question 4

**Polar molecules attract?

Answer 4

Other polar molecules and charged ions..

Question 5

**What is adhesion?

Answer 5

Polar molecules attract other polar molecules as well as charged ions.

Question 6

What happens when two water molecules come in close contact?

Answer 6

The negative oxygen end is attracted to the other water molecules positive hydrogen end.

Question 7

**What is cohesion?

Answer 7

The attraction of opposite charges (the negative oxygen and the positive hydrogen end) forms a weak bond called a hydrogen bond and the property is referred to as cohesion.

Question 8

**The combination of adhesion and cohesion result in?

Answer 8

The movement of water through plants by capillary action and surface tension - type of cohesion.

Question 9

**Because of waters polarity -

Answer 9

It is the universal solvent.

Question 10

**Why does water require more heat to increase it temperature than other liquids?

Answer 10

Because hydrogen bonds between each molecule, as you add water, must be broken to move around.

Question 11

**What is high specific heat?

Answer 11

It takes more heat to break the bonds of a water molecule than most substances.

Question 12

What happens when water cools?

Answer 12

It gives off a lot of heat.

Question 13

High heat of fusion?

Answer 13

The characteristic of water giving off a lot of heat when it cools.

Question 14

Because water takes longer to heat up and cool down, it is like an?

Answer 14

Insulator that helps maintain a steady environment when conditions fluctuate outside and within our own bodies/cells.

Question 15

What happens when water begins to freeze?

Answer 15

More and more hydrogen bonds are formed and the water molecules come more spread apart.

Question 16

What happens when ice forms?

Answer 16

It becomes less dense than the surrounding liquid water, therefore ice floats.

Question 17

**What is a mixture?

Answer 17

A combination of substances which the individual components retain their own properties. E.g., sand and salt; salt and pepper.

Question 18

**What is a solution?

Answer 18

A mixture in which one or more substances (solutea) are distributed evenly in another substance (solvent).

Question 19

**What is once substance dissolved in another and will not settle out? E.g., salt water

Answer 19

Solution.

Question 20

Organisms can’t live unless?

Answer 20

The concentration of dissolved substances stays within a specific, narrow range.

Question 21

When can chemical reactions occur?

Answer 21

When conditions are right.

Question 22

**What is a very important condition of a chemical reaction?

Answer 22

pH of a solution.

Question 23

**What does pH measure?

Answer 23

The percent of hydrogen in a substance, indicating how acidic or basic a solution is.

Question 24

**What is the pH scale for acidic?

Answer 24

0-6.9

Question 25

**What is the pH scale for basic?

Answer 25

7.1-14

Question 26

**What is the pH scale for neutral?

Answer 26

7

Question 27

**What is an acid?

Answer 27

A substance that forms hydrogen ions in water.

Question 28

**What is a base?

Answer 28

A substance that forms hydroxide ions in water.

Question 29

**What is it called with the number of H+ and OH- ions are equal?

Answer 29

The solution is neutral with a pH of 7.

Question 30

**What is surface tension?

Answer 30

The cohesive forces between liquid molecules responsible for the phenomenon called surface tension.

Question 31

**What is capillary action?

Answer 31

The movement of water within porous material due to adhesion, cohesion and surface tension.

Question 32

**Non-polar covalent bonds?

Answer 32

2 atoms share pair of electrons. The shared electrons glue 2 or more atoms together to form a molecule.

Question 33

**Polar covalent bonds?

Answer 33

A pair of electrons are unequally shared between two atoms.

Question 34

**What is a solute?

Answer 34

A substance that dissolves in a solvent to form a solution.

Question 35

**Hydrogen Bond?

Answer 35

The force of attraction between a positive and negative region of a water molecule.