Phase Diagrams and Heating Curves

Phase Diagrams and Heating/Cooling Curves

Multiple Choice

At 0.10 atm, what phase(s) can exist?

• solid, liquid or gas
• liquid or gas
• solid only
• gas only

Multiple Choice

Below the temperature of point B, this substance can exist as a ____________.

• solid only
• liquid only
• gas only
• either a solid, liquid or gas

Multiple Choice

What is the normal melting point of this substance?

• 150 °C
• 100 °C
• -50 °C
• 0 °C

Multiple Choice

What is the normal boiling point of this substance?

• 150 °C
• 100 °C
• -50 °C
• 0 °C

Multiple Choice

What state of matter is Z?

• solid 
• liquid
• gas
• supercritical fluid

Multiple Choice

What is the normal boiling point of CO₂?

• -78.5 °C
• -56.7 °C
• 31 °C
• It doesn't have a normal boiling point.

Multiple Choice

What is the normal melting point of CO₂?

• -78.5 °C
• -56.7 °C
• 31 °C
• It doesn't have a normal melting point.

Multiple Choice

At 10 atm, dry ice is heated from -100 °C to 30 °C.  What changes occur?

• freezing, then condensation
• melting only
• sublimation only
• melting, then boiling

Multiple Choice

What is true regarding CO₂ for temperatures above 31 °C?

• It can never be liquified.
• It decomposes.
• It has a high pressure.
• It is a plasma.

Multiple Choice

Based on its phase diagram, which is the most dense state for CO₂?

• gas
• liquid
• solid
• supercritical fluid

Multiple Choice

Which statement is true for carbon dioxide at -60 °C?

• All three phases are possible.
• It can exist as a solid or a gas, depending on pressure.
• It is a solid.
• With enough pressure it can be melted.

Multiple Choice

Water will boil at temperatures above 100 °C at pressures __________ 760 mmHg.

• below
• above
• equal to
• significantly below

Multiple Choice

The pressure is increased on a sample of water at 0 °C from 0 mmHg to 800 mmHg.  In order, what changes occur?

• deposition, melting
• sublimation, melting
• condensation, freezing
• deposition, freezing

Multiple Choice

What phase change(s) may occur at pressures below 4.58 mmHg?

• sublimation/deposition
• melting/freezing
• all phase changes are possible at these pressures
• vaporization/condensation

Multiple Choice

Water exists as a _____________ at 700 mmHg and 50 °C.

• solid
• liquid
• gas
• supercritical fluid

Multiple Choice

Water exists as a _____________ at 3 mmHg and 50 °C.

• solid
• liquid
• gas
• supercritical fluid

Multiple Choice

What change occurs from E to C?

• sublimation
• freezing
• melting
• boiling

Multiple Choice

What is the normal boiling point of this substance?

• 150 °C
• 100 °C
• -50 °C
• 0 °C

Multiple Choice

What state of matter is Y?

• solid 
• liquid
• gas
• supercritical fluid

Multiple Choice

What state of matter is X?

• solid 
• liquid
• gas
• supercritical fluid

Multiple Choice

What is the freezing point of the substance?

• 0^oC

• 60^oC

• 120^oC

• 180^oC

Multiple Choice

What is the boiling point for this substance?

• 40 °C

• 60 °C

• 120 °C

• 140 °C

Multiple Choice

In which region(s) of the graph would condensation occur?

• Region A-C

• Region C-E

• Region E-G

• Region G-I

• Region I-K

Multiple Choice

In which region(s) of the graph would the substance be freezing?

• Region A-C

• Region C-E

• Region E-G

• Region G-I

• Region I-K

Multiple Choice

In which region(s) of the graph would the substance be melting?

• No melting occurs on this graph

• Region C-E

• Region E-G

• Region G-I

• Region I-K

Multiple Choice

This curve indicates what about the heat energy?

• Heat energy is being added or absorbed

• Heat energy is being released

Multiple Choice

The freezing and melting points of water are the same.

• True
• False

Multiple Choice

The melting point of the sample is

• -60 ºC

• -100 ºC

• 60 ºC

• 100 ºC

Multiple Choice

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

• A-B only. 
• A-B, C-D, E-F
• B-C only. 
• B-C, D-E

Multiple Choice

Describe the substance between letters D and E. 

• Gas
• Liquid
• Melting
• Evaporating

Multiple Choice

Describe the substance between letters A and B. 

• Solid
• Liquid
• Melting
• Evaporating

Multiple Choice

In which region(s) of the graph does boiling take place?

• Region 2
• Region 3
• Region 4
• Region 5

Multiple Choice

In which region(s) of the graph would the substance be a gas only?

• Region 2
• Region 3
• Region 4
• Region 5

Multiple Choice

In which region(s) of the graph would the substance be a solid and a liquid?

• Region 1
• Region 2
• Region 3
• Region 4

Multiple Choice

In which region(s) of the graph would the substance be a solid only?

• Region 1
• Region 2
• Region 3
• Region 4

Multiple Choice

In which region(s) of the graph would the substance only be in one phase?

• Region 1, 3, & 5
• Region 2 & 4
• Region 1 only
• Region 1 & 2

Multiple Choice

In which region(s) of the graph does a phase change occur?

• Region 1, 3, & 5
• Region 2 & 4
• Region 1 only
• Region 1 & 2

Multiple Choice

This curve indicates what about the heat energy?

• heat energy is being added or absorbed
• heat energy is being removed

Multiple Choice

In which region(s) does temperature increase?

• Region 1, 3, & 5
• Region 2 & 4
• Region 1 only
• Region 1 & 2

Multiple Choice

In which region(s) does temperature remain constant?

• Region 1, 3, & 5
• Region 2 & 4
• Region 1 only
• Region 1 & 2

That is your lesson on Phase Diagrams and Heating/Cooling Curves.

Make sure to add these conversions to your notes:

1 atm=760 mm of Hg

1 atm= 14.7 psi

1 atm= 101.3 kPa