# Chemical formula and heat

In my Physical Science class, we are learning about chemical formulas and how to balance them. I balanced this equation:

$$\ce{Fe2O3 + Al -> Fe + Al2O3}$$

One of the other students asked me if this chemical formula releases or absorbs heat.

Could anyone help me give a great explanation for this question?

• en.wikipedia.org/wiki/Aluminothermic_reaction Apr 27 '15 at 21:27
• Check $\Delta H$ tables and calculate if the reaction is endothermic or exothermic. Apr 27 '15 at 21:38
• @Sydney U: Please note currently (22:10 UTC time), your reaction equation is not yet balanced correctly. Apr 27 '15 at 22:12
• Look up thermite for more information on this displacement reaction. My students enjoyed seeing it demonstrated. Apr 28 '15 at 0:31

The best way to solve this problem is to look at the $\Delta H$ charts found online. Using the simple equation below will give you the answer.
$$\sum \Delta H_{\text{Products}} - \sum \Delta H_\text{Reactants} = \Delta H_{\text{Reaction}}$$ If the $\Delta H$ is positive in sign then the reaction is endothermic and if it is negative in sign then it is exothermic.