ScienceAges 16-18

Specific latent heat (Q = mL)

Use Q = mL to calculate the thermal energy absorbed or released during melting or boiling at constant temperature. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 16-18

Specific latent heat (Q = mL)

Take your time. Show your thinking.

1. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 440 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 10 kg · L = 440 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
2. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 220 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 4 kg · L = 220 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
3. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 3 kg · L = 210 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
4. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 280 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 2 kg · L = 280 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
5. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 2 kg · L = 420 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
6. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 390 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 3 kg · L = 390 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
7. A 8 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 160 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 8 kg · L = 160 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
8. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 380 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 11 kg · L = 380 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
9. A 9 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 140 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 9 kg · L = 140 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
10. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 7 kg · L = 420 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
11. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 120 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 7 kg · L = 120 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
12. A 1 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 310 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 1 kg · L = 310 kJ/kg · Latent Heat: Q = mL (ΔT = 0)

12 questions · Seed 42 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 16-18

Specific latent heat (Q = mL)

Answers and reasoning. Review before teaching.

1. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 440 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
4400 kJ
During a change of state at constant temperature, Q = m × L = 10 kg × 440 kJ/kg = 4400 kJ.
2. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 220 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
880 kJ
During a change of state at constant temperature, Q = m × L = 4 kg × 220 kJ/kg = 880 kJ.
3. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
630 kJ
During a change of state at constant temperature, Q = m × L = 3 kg × 210 kJ/kg = 630 kJ.
4. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 280 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
560 kJ
During a change of state at constant temperature, Q = m × L = 2 kg × 280 kJ/kg = 560 kJ.
5. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
840 kJ
During a change of state at constant temperature, Q = m × L = 2 kg × 420 kJ/kg = 840 kJ.
6. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 390 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1170 kJ
During a change of state at constant temperature, Q = m × L = 3 kg × 390 kJ/kg = 1170 kJ.
7. A 8 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 160 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1280 kJ
During a change of state at constant temperature, Q = m × L = 8 kg × 160 kJ/kg = 1280 kJ.
8. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 380 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
4180 kJ
During a change of state at constant temperature, Q = m × L = 11 kg × 380 kJ/kg = 4180 kJ.
9. A 9 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 140 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1260 kJ
During a change of state at constant temperature, Q = m × L = 9 kg × 140 kJ/kg = 1260 kJ.
10. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
2940 kJ
During a change of state at constant temperature, Q = m × L = 7 kg × 420 kJ/kg = 2940 kJ.
11. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 120 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
840 kJ
During a change of state at constant temperature, Q = m × L = 7 kg × 120 kJ/kg = 840 kJ.
12. A 1 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 310 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
310 kJ
During a change of state at constant temperature, Q = m × L = 1 kg × 310 kJ/kg = 310 kJ.

12 questions · Seed 42 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 16-18

Specific latent heat (Q = mL)

Take your time. Show your thinking.

1. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 440 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 10 kg · L = 440 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
2. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 220 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 4 kg · L = 220 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
3. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 3 kg · L = 210 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
4. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 280 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 2 kg · L = 280 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
5. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 2 kg · L = 420 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
6. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 390 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 3 kg · L = 390 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
7. A 8 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 160 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 8 kg · L = 160 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
8. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 380 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 11 kg · L = 380 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
9. A 9 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 140 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 9 kg · L = 140 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
10. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 7 kg · L = 420 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
11. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 120 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 7 kg · L = 120 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
12. A 1 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 310 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 1 kg · L = 310 kJ/kg · Latent Heat: Q = mL (ΔT = 0)

12 questions · Seed 42 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 16-18

Specific latent heat (Q = mL)

Answers and reasoning. Review before teaching.

1. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 440 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
4400 kJ
During a change of state at constant temperature, Q = m × L = 10 kg × 440 kJ/kg = 4400 kJ.
2. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 220 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
880 kJ
During a change of state at constant temperature, Q = m × L = 4 kg × 220 kJ/kg = 880 kJ.
3. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
630 kJ
During a change of state at constant temperature, Q = m × L = 3 kg × 210 kJ/kg = 630 kJ.
4. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 280 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
560 kJ
During a change of state at constant temperature, Q = m × L = 2 kg × 280 kJ/kg = 560 kJ.
5. A 2 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
840 kJ
During a change of state at constant temperature, Q = m × L = 2 kg × 420 kJ/kg = 840 kJ.
6. A 3 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 390 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1170 kJ
During a change of state at constant temperature, Q = m × L = 3 kg × 390 kJ/kg = 1170 kJ.
7. A 8 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 160 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1280 kJ
During a change of state at constant temperature, Q = m × L = 8 kg × 160 kJ/kg = 1280 kJ.
8. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 380 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
4180 kJ
During a change of state at constant temperature, Q = m × L = 11 kg × 380 kJ/kg = 4180 kJ.
9. A 9 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 140 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1260 kJ
During a change of state at constant temperature, Q = m × L = 9 kg × 140 kJ/kg = 1260 kJ.
10. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 420 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
2940 kJ
During a change of state at constant temperature, Q = m × L = 7 kg × 420 kJ/kg = 2940 kJ.
11. A 7 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 120 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
840 kJ
During a change of state at constant temperature, Q = m × L = 7 kg × 120 kJ/kg = 840 kJ.
12. A 1 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 310 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
310 kJ
During a change of state at constant temperature, Q = m × L = 1 kg × 310 kJ/kg = 310 kJ.

12 questions · Seed 42 · Age guidance, not curriculum certification