Change in Temperature

A change in temperature is characteristic of a chemical change. During an experiment, one could dip a thermometer into a beaker or Erlenmeyer Flask to verify a temperature change. If temperature increases, as it does in most reactions, a chemical change is likely to be occurring. This is different from the physical temperature change. During a physical temperature change, one substance, such as water is being heated. However, in this case, one compound is mixed in with another, and these reactants produce a product. When the reactants are mixed, the temperature change caused by the reaction is an indicator of a chemical change.

Figure: Violent Reaction (Fireworks) with heat as a product

As an example of a exothermic reaction, if Fe2O3 is mixed with Al and ignighted (often with burning Mg), then the thermite reaciton is initiated

This reaction generates heat as a product and is (very) exothermic.

However, physical changes can be exothermic or endothermic. The melting of an ice cube, which is endothermic, is a change in a physical property and not composition. Thus, it is a physical change.

مواضيع ذات صلة

تسمية المركبات الجزيئية Molecular Compounds

تسمية المركبات الأيونية Ionic Compounds

تسمية المركبات Naming Compounds

صيغ المركبات الأيونية Formula of Ionic Compounds

الصيغ الأولية Empirical Formulas

الصيغ الجزيئية Molecular Formulas

الأيونات Ions

الجزيئات Molecules

الجدول الدوري The Periodic Table

العدد الذري وعدد الكتلة والنظائر Atomic Number, Mass Number and Isotopes

النيوترون The Neutron

البروتون والنواة The Proton and the Nucleus