Chapter 11 (section 6)

Question 1

Define sublimation

Answer 1

The phase transition from solid to gase

Question 2

Define deposition

Answer 2

The phase transition from gas to solid

Question 3

Define melting point

Answer 3

The temperature at which the molecules of a solid have enough thermal energy to overcome intermolecular forces and become a liquid

Question 4

define melting (fusion)

Answer 4

The phase transiton from solid to liquid

Question 5

define freezing

Answer 5

The phase transition from liquid to solid

Question 6

Define heat of fusion (∆fusHº)

Answer 6

The amount of heat required to melt 1 mol of a solid

Question 7

Freezing is an ____ process

Answer 7

exothermic

Question 8

Melting is a ____ process

Answer 8

endothermic

Question 9

The heat of fusion is ____ because melting is endothermic

Answer 9

positive

Question 10

Why does it take less energy to melt 1 mol of ice into water than it takes to vaporize 1 mol of water into steam?

Answer 10

because vaporization requires complete separation of the molecules from one another, so the intermolecular forces must be completely overcome. Melting only requires that intermolecular forces be partially overcome