ScienceAges 13-15

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 13-15

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 = 170 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 10 kg · L = 170 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
2. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 190 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 10 kg · L = 190 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
3. A 12 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 = 12 kg · L = 380 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
4. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 340 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 5 kg · L = 340 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
5. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 400 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 4 kg · L = 400 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
6. A 12 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 = 12 kg · L = 220 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
7. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 200 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 5 kg · L = 200 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
8. A 8 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 = 8 kg · L = 310 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
9. A 5 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 = 5 kg · L = 160 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
10. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 11 kg · L = 210 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
11. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 330 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 4 kg · L = 330 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
12. A 5 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 = 5 kg · L = 220 kJ/kg · Latent Heat: Q = mL (ΔT = 0)

12 questions · Seed 43 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 13-15

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 = 170 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1700 kJ
During a change of state at constant temperature, Q = m × L = 10 kg × 170 kJ/kg = 1700 kJ.
2. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 190 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1900 kJ
During a change of state at constant temperature, Q = m × L = 10 kg × 190 kJ/kg = 1900 kJ.
3. A 12 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.
4560 kJ
During a change of state at constant temperature, Q = m × L = 12 kg × 380 kJ/kg = 4560 kJ.
4. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 340 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1700 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 340 kJ/kg = 1700 kJ.
5. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 400 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1600 kJ
During a change of state at constant temperature, Q = m × L = 4 kg × 400 kJ/kg = 1600 kJ.
6. A 12 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.
2640 kJ
During a change of state at constant temperature, Q = m × L = 12 kg × 220 kJ/kg = 2640 kJ.
7. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 200 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1000 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 200 kJ/kg = 1000 kJ.
8. A 8 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.
2480 kJ
During a change of state at constant temperature, Q = m × L = 8 kg × 310 kJ/kg = 2480 kJ.
9. A 5 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.
800 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 160 kJ/kg = 800 kJ.
10. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
2310 kJ
During a change of state at constant temperature, Q = m × L = 11 kg × 210 kJ/kg = 2310 kJ.
11. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 330 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1320 kJ
During a change of state at constant temperature, Q = m × L = 4 kg × 330 kJ/kg = 1320 kJ.
12. A 5 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.
1100 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 220 kJ/kg = 1100 kJ.

12 questions · Seed 43 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

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 = 170 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 10 kg · L = 170 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
2. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 190 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 10 kg · L = 190 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
3. A 12 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 = 12 kg · L = 380 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
4. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 340 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 5 kg · L = 340 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
5. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 400 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 4 kg · L = 400 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
6. A 12 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 = 12 kg · L = 220 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
7. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 200 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 5 kg · L = 200 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
8. A 8 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 = 8 kg · L = 310 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
9. A 5 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 = 5 kg · L = 160 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
10. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 11 kg · L = 210 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
11. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 330 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
Mass m = 4 kg · L = 330 kJ/kg · Latent Heat: Q = mL (ΔT = 0)
12. A 5 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 = 5 kg · L = 220 kJ/kg · Latent Heat: Q = mL (ΔT = 0)

12 questions · Seed 43 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

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 = 170 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1700 kJ
During a change of state at constant temperature, Q = m × L = 10 kg × 170 kJ/kg = 1700 kJ.
2. A 10 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 190 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1900 kJ
During a change of state at constant temperature, Q = m × L = 10 kg × 190 kJ/kg = 1900 kJ.
3. A 12 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.
4560 kJ
During a change of state at constant temperature, Q = m × L = 12 kg × 380 kJ/kg = 4560 kJ.
4. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 340 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1700 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 340 kJ/kg = 1700 kJ.
5. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 400 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1600 kJ
During a change of state at constant temperature, Q = m × L = 4 kg × 400 kJ/kg = 1600 kJ.
6. A 12 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.
2640 kJ
During a change of state at constant temperature, Q = m × L = 12 kg × 220 kJ/kg = 2640 kJ.
7. A 5 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 200 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1000 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 200 kJ/kg = 1000 kJ.
8. A 8 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.
2480 kJ
During a change of state at constant temperature, Q = m × L = 8 kg × 310 kJ/kg = 2480 kJ.
9. A 5 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.
800 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 160 kJ/kg = 800 kJ.
10. A 11 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of vaporisation (boiling) L = 210 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
2310 kJ
During a change of state at constant temperature, Q = m × L = 11 kg × 210 kJ/kg = 2310 kJ.
11. A 4 kg sample of a substance undergoes a change of state at constant temperature with specific latent heat of fusion (melting) L = 330 kJ/kg. Using Q = mL, calculate the thermal energy required in kJ.
1320 kJ
During a change of state at constant temperature, Q = m × L = 4 kg × 330 kJ/kg = 1320 kJ.
12. A 5 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.
1100 kJ
During a change of state at constant temperature, Q = m × L = 5 kg × 220 kJ/kg = 1100 kJ.

12 questions · Seed 43 · Age guidance, not curriculum certification