Calculator Input
Example Data Table
| Case | Input | Formula | Expected Result |
|---|---|---|---|
| Water Heating | 100 g, 4.184 J/g°C, 25°C | q = m × c × ΔT | 10.46 kJ |
| Molar Enthalpy | 10 kJ, 2 mol | ΔH = q ÷ n | 5 kJ/mol |
| Formation Reaction | Products -393.5, Reactants -74.8 | Σ products − Σ reactants | -318.7 kJ/mol |
| Energy Conversion | 1 kcal | kcal × 4184 | 4184 J |
Formula Used
Heat method: ΔH = q = m × c × ΔT
Molar method: ΔH = q ÷ n
Formation method: ΔH°rxn = ΣνΔHf° products − ΣνΔHf° reactants
Energy conversion: Converted energy = input energy × conversion factor
A positive value usually means heat is absorbed. A negative value usually means heat is released.
How to Use This Calculator
- Select the calculation type that matches your data.
- Enter heat, mass, temperature change, moles, or formation totals.
- Choose the correct units for every input.
- Set the number of decimal places.
- Press the calculate button.
- Review the result, formula, and step-by-step working.
- Use the CSV or PDF button to save the result.
Understanding Delta H
What Delta H Means
Delta H measures enthalpy change. It shows heat change at constant pressure. The value helps describe heating, cooling, reactions, and phase changes. It is common in chemistry, physics, engineering, and thermal studies.
Why Units Matter
Units change the size of the answer. Joules and kilojoules are common metric units. Calories and kilocalories are also used. BTU is useful in energy and heating work. This tool converts these units before calculating the final result.
Heat Method
The heat method uses mass, specific heat, and temperature change. It is useful when a material warms or cools. Water is a common example. Its specific heat is often written as 4.184 J/g°C. The calculator converts mass and temperature difference before solving.
Molar Method
The molar method divides heat by moles. This gives energy per mole. It is useful for comparing reactions. A reaction with a large negative value releases more heat per mole. A positive value means the reaction absorbs heat.
Formation Method
The formation method uses standard enthalpy values. First multiply each formation value by its coefficient. Then add product values. Add reactant values separately. Subtract the reactant total from the product total. This gives the reaction enthalpy.
Practical Use
Students can use this calculator for homework and lab reports. Teachers can create examples quickly. Engineers can check simple heat changes. The step display helps users see each conversion. The export buttons make record keeping easier.
Reading the Sign
A positive delta H points to an endothermic process. Heat enters the system. A negative delta H points to an exothermic process. Heat leaves the system. The sign is just as important as the number.
FAQs
What is delta H?
Delta H is the enthalpy change of a system. It shows heat absorbed or released at constant pressure during heating, cooling, or reaction.
What does positive delta H mean?
A positive delta H means the process absorbs heat. This type of process is usually called endothermic.
What does negative delta H mean?
A negative delta H means the process releases heat. This type of process is usually called exothermic.
Can I calculate delta H from mass and temperature?
Yes. Use the heat method. Enter mass, specific heat, and temperature change. The calculator applies q = m × c × ΔT.
How is molar delta H calculated?
Molar delta H is calculated by dividing heat energy by moles. The common unit is kJ/mol.
What are formation enthalpy totals?
They are summed standard formation values after multiplying each compound by its balanced equation coefficient.
Can this calculator convert energy units?
Yes. It supports joules, kilojoules, calories, kilocalories, and BTU for quick energy conversion.
Can I export the answer?
Yes. After calculation, use the CSV or PDF button to download the result and calculation steps.