States of Matter

What is the relationship between KE and temperature?

• They change all the time

• They both deal with matter

• There is no relationship

• They are directly proportional

Tags

NGSS.HS-PS3-2

What external pressure would allow ethanol to boil at 40 degrees Celsius?

• 20 kPa

• 40 kPa

• 55 kPa

• 100 kPa

What is the normal boiling point of chloroform?

• 100 degrees Celsius

• 10 degrees Celsius

• 80 degrees Celsius

• 60 degrees Celsius

Water normally boils at 100 degrees Celsius (at sea level atmospheric pressure = 101.3 kPa). Altitude is the height above sea level. As the altitude increases, there is less atmosphere above a substance pressing down on it. This decrease in pressure causes a substance to boil at a lower temperature. This is why water boils at lower temperatures on a mountain than it does at sea level. If the pressure of water were decreased to 80 kPa, at what temp would water boil?

• about 75 degrees Celsius

• about 50 degrees Celsius

• about 95 degrees Celsius

• about 100 degrees Celsius

Different substances have different levels of attraction between their molecules. Substances with a strong attraction between their molecules are said to have a strong IMF (intermolecular force), so it takes more energy to boil them. Substances with a weaker attraction between their molecules have a weaker IMF and are more volatile, so it takes less energy to boil them. Which liquid has the strongest intermolecular forces?

• Chloroform

• Ethanol

• Water

• Ethanoic acid

Tags

NGSS.HS-PS1-3

Convert 380 mmHg to atm.

• 50.65 atm

• 760 atm

• 0.5 atm

• 2 atm

What is happening to the substance as heat is applied?

• IMF increases, Kinetic Energy increases during the non-horizontal portions, and Potential energy increases during the horizontal portions.

• IMF decreases, Kinetic Energy increases during the non-horizontal portions, and Potential energy increases during the horizontal portions.

• IMF increases, Kinetic Energy decreases during the non-horizontal portions, and Potential energy decreases during the horizontal portions.

• IMF decreases, Kinetic Energy decreases during the non-horizontal portions, and Potential energy decreases during the horizontal portions.

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-2

What is happening to the substance at 140 degrees C?

• The substance is melting.

• The substance is boiling

• The substance is a liquid

• The substance is a gas

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Select ALL of the following statements that are TRUE.

• Solid is present at 4 minutes

• Potential energy is constant from 6 to 8 minutes

• Both gas and liquid are present at 16 minutes

• Kinetic energy is increasing from 14 to 16 minutes

• Kinetic energy and temperature increase from 10 to 12 minutes

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-2

NGSS.HS-PS1-4

From 6 to 8 minutes, the potential energy increases as heat is added to the substance. This increase in potential energy weakens the IMF (intermolecular forces that hold the molecules together). Molecules in a solid have a strong attraction to each other (strong IMF), whereas the molecules in a liquid have a moderate attraction to each other (moderate IMF). Since solids have a strong IMF and liquids have a moderate IMF, this weakening of the IMF causes the substance to change from a solid to a liquid. In the liquid phase, the molecules are able to move around more freely than in the solid phase. As this heat is added during a phase change, what happens to the temperature of the substance?

• Increases

• Decreases

• Remains constant

• Not enough information to determine

Tags

NGSS.HS-PS3-4