Calorimetry Calculator
Find the equilibrium temperature when two water masses mix.
Results
Calorimetry determines the final temperature when two substances at different temperatures are mixed. Heat flows from the hotter object to the cooler one until they reach thermal equilibrium. This calculator assumes both substances are water with the same specific heat (4186 J/kg·°C) and no heat loss to the environment.
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Frequently asked questions
Tf = (0.5 × 90 + 1 × 20) / (0.5 + 1) = 65/1.5 = 43.33°C. The larger cold mass dominates, pulling the final temperature closer to 20°C.
Q = m × c × (Ti - Tf). If 0.5 kg at 90°C cools to 43.33°C, Q = 0.5 × 4186 × 46.67 = 97,659 joules or 97.66 kJ.
Larger masses carry more thermal energy. Mixing equal temperatures but 2:1 mass ratio, the final temp is 2/3 of the way toward the larger mass's temperature.
Only if they have the same specific heat. For different materials, use Q = m1c1(T1-Tf) = m2c2(Tf-T2) and solve for Tf. Oil (c=2000) heats differently than water (c=4186).
In practice, add the calorimeter's heat capacity. A typical foam cup calorimeter absorbs about 10-15 J/°C. Professional calorimeters are calibrated to account for this precisely.