Thermochemistry Calculator

Thermochemistry Calculator is a useful chemistry tool that calculates energy changes that occur during a chemical reaction. When a reaction occurs, energy is either released (exothermic reaction) or absorbed (endothermic reaction) — and this energy change is measured as enthalpy (ΔH).

With this calculator, you can easily perform enthalpy change (ΔH), heat (q), and specific heat calculations. This tool is helpful for both students and researchers who want to understand the behavior of reaction energy.

What is thermochemistry?

Thermochemistry is a branch of chemistry that studies the heat changes of chemical reactions. In every reaction, bonds break and form—and this process is accompanied by the transfer of energy.

  • Exothermic Reaction: Energy (heat) is released → ΔH becomes negative.
    • Example: Combustion of methane
    • CH4​+2O2​→CO2​+2H2​O+heat
  • Endothermic Reaction: Energy is absorbed → ΔH becomes positive.
    • Example: Photosynthesis
    • 6CO2​+6H2​O+sunlight→C6​H12​O6​+6O2

How to use:

  • Input the reaction data (mass, specific heat, and temperature change).
  • If you need ΔH or q, select the corresponding option.
  • Click the Calculate button and you will get an instant result.
  • The calculator also provides a short explanation along with the result to clarify the concept.

Important Points:

  • If ΔH is negative, the reaction is exothermic.
  • If ΔH is positive, the reaction is endothermic.
  • Keep the units consistent—heat (Joules), mass (grams), temperature (°C or K).
  • Always note: heat exchange occurs with the environment, not within the system.

FAQs

Q1. What is the main purpose of thermochemistry?
Thermochemistry studies how energy changes or transfers during chemical reactions — as heat or work.

Q2. Does an exothermic reaction absorb heat?
No, an exothermic reaction releases heat.

Q3. What does the sign of ΔH show?
A positive ΔH means heat is absorbed (endothermic reaction).
A negative ΔH means heat is released (exothermic reaction).

Q4. What is the role of specific heat?
Specific heat tells how much heat is needed to raise the temperature of 1 gram of a substance by 1°C.

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