3.5 Phase Changes

Question 1

a chemical change

Answer 1

a change where new substances are formed

Question 2

a physical change

Answer 2

a change in the phase of a substance, such that no new substances are formed

Question 3

true or false: chemical changes are frequently accompanied by physical changes

Answer 3

TRUE

Question 4

melting temperature

Answer 4

the temperature at which a solid changes in the liquid phase

Question 5

freezing temperature

Answer 5

the temperature at which liquid changes into the solid phase

Question 6

At the melting/freezing temperature, the liquid and gas phase _______.

Answer 6

co-exist

Question 7

boiling temperature

Answer 7

temperature at which a liquid changes into a the gas phase

Question 8

condensation temperature

Answer 8

the temperature at which a gas changes into the liquid phase

Question 9

On the sloping portions of a phase changing graph..

Answer 9

all the heat is used to warm the substance so the temperature rises

Question 10

On the level portion os a phase changing graph…

Answer 10

the substance contains so much heat energy that it cannot absorb more heat and stay in the same phase, all the heat is used to change phase so the temperature doesn’t change and the graph levels off