Khan Academy

Question 1

Polar Molecule

Answer 1

An uncharged molecule with partially positive and partially negative regions

Question 2

Cohesion

Answer 2

The attraction of molecules for other molecules of the same kind

Question 3

Adhesion

Answer 3

The attraction of molecules for other molecules of a different kind

Question 4

Density

Answer 4

The mass per unit volume of a substance

Question 5

Specific Heat Capacity

Answer 5

The amount of heat needed to raise the temperature of one gram of a substance by one degrees Celsius

Question 6

Heat of Vaporization

Answer 6

The amount of energy needed to change one gram of a liquid substance to a gas at a constant temperature

Question 7

What are the properties of water?

Answer 7

1. Water is polar
2. Water is an excellent solvent
3. Water has high heat capacity
4. Water has high heat of vaporization
5. Water has cohesive and adhesive properties
6. Water is less dense as a solid than as a liquid

Question 8

Explain: Water is polar

Answer 8

Has a partial negative charge because of the oxygen and partial positive charge because of the hydrogen

Question 9

Explain: Water is an excellent solvent

Answer 9

It can form bonds to pull apart ionic and polar molecules due to its polarity

Question 10

Explain: Water has a high heat capacity

Answer 10

It takes a lot of energy to raise the temperature of water, so water can regulate the temperature of its environment

Question 11

Explain: Water has high heat of vaporization

Answer 11

Vaporization is used to cool humans and animals off because the water takes the heat with it as it evaporates

Question 12

Explain: Water has cohesive and adhesive properties

Answer 12

Water has strong cohesive forces due to hydrogen bonding, which leads to surface tension of water. It also has adhesive properties that allow it to stick to substances other than itself

Question 13

Explain: Water is less dense as a solid than as a liquid

Answer 13

Ice has a crystalline structure that cause the molecules to be further apart than in liquid form

Question 14

What is a common misconception of water?

Answer 14

That it dissolves everything because it is the “universal solvent”

Question 15

Why can’t water dissolve everything?

Answer 15

Water can’t dissolve nonpolar molecules because they lack partial positive and partial negative charges, therefore are not attracted to these molecules