Heat of Phase Changes

Which equation should you use:

How much heat is required to melt 10.0 grams of H₂O?

• Q =mΔH_vap

• Q =mCΔT

• Q =m(-ΔH_fus)

• Q =mΔH_fus

Which equation should you use:

How much heat is released when 20.0 grams of H₂O freeze?

• Q =mΔH_vap

• Q =mCΔT

• Q =m(-ΔH_fus)

• Q =mΔH_fus

Which equation should you use:

How much heat is required to vaporize 15.0 grams of H₂O?

• Q =mΔH_vap

• Q =mCΔT

• Q =m(-ΔH_vap)

• Q =mΔH_fus

Which equation should you use:

How much heat is released when 35.0 g of H₂O condenses?

• Q =mΔH_vap

• Q =mCΔT

• Q =m(-ΔH_vap)

• Q =mΔH_fus

Which equation(s) should you use:

How much energy is required to heat 35.0 grams of H₂O from 10°C to 80°C?

• only Q =mΔH_vap

• only Q =mCΔT

• Q =mCΔT and Q =mΔH_vap

• Q =mCΔT and Q =mΔH_fus

Tags

NGSS.HS-PS3-4

Which equation(s) should you use:

How much energy is required to heat 12.0 grams of H₂O from -15°C to 80°C?

• only Q =mCΔT

• Q =mCΔT and Q =mΔH_fus

• Q =mCΔT and Q =mΔH_vap

• only Q =mΔH_fus

Which equation(s) should you use:

How much energy is released when 18.0 grams of H₂O is cooled from 115°C to 80°C?

• only Q =mCΔT

• Q =mCΔT and Q =mΔH_fus

• Q =mCΔT and Q =m(-ΔH_vap)

• only Q =m(-ΔH_vap)

Tags

NGSS.HS-PS3-4

Which equation(s) should you use:

What mass of water absorbs 3320 J when it is heated from 10°C to 50°C?

• only Q =mCΔT

• Q =mCΔT and Q =mΔH_fus

• Q =mCΔT and Q =m(-ΔH_vap)

• only Q =mΔH_vap

Tags

NGSS.HS-PS3-1

Which of the following is an ENDOTHERMIC phase change?

• Vaporization

• Freezing

• Condensation

• Deposition

Tags

NGSS.HS-PS3-4

Which of the following is an EXOTHERMIC phase change?

• melting

• sublimation

• freezing

• vaporization

Tags

NGSS.HS-PS1-4