Thermal Equilibrium Calculator

Calculate the final temperature when two objects or systems exchange heat until thermal equilibrium

Calculate Thermal Equilibrium

Choose whether to include latent heat for phase transitions (melting, freezing, vaporization)

Object 1 (Lower Temperature)

kg
°C

Specific Heat: 4,181.3 J/(kg·K)

Object 2 (Higher Temperature)

kg
°C

Specific Heat: 4,181.3 J/(kg·K)

Thermal Equilibrium Results

0.00°C
Celsius
32.00°F
Fahrenheit
273.15K
Kelvin
Heat Transfer (Object 1)
0.000 kJ
Heat Lost
Heat Transfer (Object 2)
0.000 kJ
Heat Lost
Energy Balance Check:0.000 J

Should be close to zero for energy conservation (Q₁ + Q₂ = 0)

Formula used:

T_final = (m₁c₁T₁ + m₂c₂T₂) / (m₁c₁ + m₂c₂)

Q = mcΔT

Equilibrium Analysis

Example Calculation

Ice and Hot Water Mixing

Object 1: 100 g ice at 0°C

Object 2: 500 g water at 20°C

Specific heat of water: 4,181.3 J/(kg·K)

Latent heat of fusion: 334,000 J/kg

Solution

Without phase change: T_f = (0.1×4181×0 + 0.5×4181×20)/(0.1×4181 + 0.5×4181)

T_f = (0 + 41,810)/(418.1 + 2090.5) = 41,810/2508.6 = 16.67°C

With melting: Ice melts first (334 kJ), then heats to final temperature

Result: Approximately 13.3°C (accounting for melting energy)

Zeroth Law of Thermodynamics

0

Thermal Equilibrium

Objects at same temperature = no heat transfer

Transitive Property

If A=B and B=C in temperature, then A=C

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Temperature Scale

Establishes basis for temperature measurement

Heat Transfer Mechanisms

ConductionContact
ConvectionFluid Motion
RadiationEM Waves

Heat flows from high to low temperature until equilibrium

Physics Tips

Final temperature is always between initial temperatures

Energy is conserved: Q₁ + Q₂ = 0

Higher specific heat = more energy to change temperature

Phase changes require additional latent heat energy

Understanding Thermal Equilibrium

What is Thermal Equilibrium?

Thermal equilibrium occurs when two or more objects reach the same temperature and no longer exchange heat. This fundamental concept is described by the zeroth law of thermodynamics and forms the basis for temperature measurement.

Heat Transfer Process

  • Heat flows from high to low temperature objects
  • Rate depends on temperature difference and materials
  • Process continues until temperatures equalize
  • Total energy is conserved throughout the process

Mathematical Framework

Q = mcΔT

Q₁ + Q₂ = 0

T_f = (m₁c₁T₁ + m₂c₂T₂)/(m₁c₁ + m₂c₂)

  • Q: Heat transferred (Joules)
  • m: Mass of object (kg)
  • c: Specific heat capacity (J/kg·K)
  • ΔT: Temperature change (K or °C)
  • T_f: Final equilibrium temperature

Note: For phase changes, add latent heat: Q = mL

Phase Changes and Latent Heat

When substances undergo phase transitions (melting, freezing, vaporization, condensation), additional energy called latent heat is required. This energy doesn't change temperature but changes the molecular structure of the material.

Melting/Freezing

Latent heat of fusion

Water: 334 kJ/kg

Vaporization/Condensation

Latent heat of vaporization

Water: 2,260 kJ/kg

Total Energy

Q_total = Q_sensible + Q_latent

Q = mcΔT + mL