Phase Changes

Between which points is the temperature of the substance remaining constant?

• A-B only

• A-B, C-D, and E-F

• B-C only

• B-C and D-E

The melting point of the sample is

• -60 ºC

• 20 ºC

• 60 ºC

• 100 ºC

Which letter indicates where water is in both the solid and liquid phase at the same time?

• A

• B

• C

• D

• E

In which region(s) does temperature increase?

• Region C only

• Regions B and D

• Regions A, C, and E

• Regions A and B

In which region(s) of the heating curve would water be a liquid and a gas at the same time?

• A

• B

• C

• D

• E

Describe the substance at letter A.

• Solid

• Liquid

• Melting

• Evaporating

How many states of matter are present during line segment BC?

• One

• Two

• Three

• Depends on the temperature

In a heating curve, diagonal lines indicate temperature is __________, while flat lines indicate temperature is __________.

• Constant, changing

• Changing, constant

NaCl was heated starting at an initial temperature of 0°C. The heating curve is shown in the picture. What is the melting point of this substance?

• 0°C

• 801°C

• 1000°C

• 1465°C

Describe the substance at letters D.

• Gas

• Liquid

• Melting

• Evaporating