Phase Changes and Heat Calculations

Mrs. Mancuso explains heating and cooling curves, focusing on phase changes such as melting, freezing, vaporization, and condensation. She discusses the roles of kinetic and potential energy during these changes and introduces heat formulas like Q=MCΔT, heat of fusion, and heat of vaporization, providing examples of how to calculate heat required for phase changes.

What does the temperature in a heating and cooling curve represent?

• Potential energy

• Kinetic energy

• Chemical energy

• Thermal energy

What happens to a solid at its melting point?

• It becomes a gas

• It remains a solid

• It becomes a plasma

• It becomes a liquid

During which phase change does a liquid become a gas?

• Freezing

• Boiling

• Melting

• Condensing

What happens to kinetic energy during the plateau phases of a heating curve?

• It increases

• It decreases

• It fluctuates

• It remains constant

What is the term for the phase change from liquid to solid?

• Freezing

• Melting

• Vaporizing

• Condensing

Which phase change is described as vaporizing?

• Solid to liquid

• Liquid to gas

• Gas to liquid

• Liquid to solid

What is the formula used when the temperature is changing in a heating curve?

• Q = mHf

• Q = mcΔT

• Q = mL

• Q = mHv

What is the specific heat capacity of water used in heat calculations?

• 2.18 J/g°C

• 4.18 J/g°C

• 3.18 J/g°C

• 5.18 J/g°C

Which formula is used for calculating the heat during the melting phase?

• Q = mHv

• Q = mL

• Q = mcΔT

• Q = mHf

What is the heat of vaporization value for water used in calculations?

• 334 J/g

• 1000 J/g

• 418 J/g

• 2260 J/g