Evenly mixing iron powder and sulfur powder, heating until one end is red and hot, and stopping heating; Until the whole mixture is red and hot, forming a black block!

The temperature of the object when it is red and hot-600 degrees Celsius!

Exothermic reaction refers to a chemical reaction that releases heat, which is called exothermic reaction.

1. The exothermic reactions that junior high school students need to know mainly include

All combustion reactions (must be mastered)

2. The reaction between acid and metal (must be mastered)

3. Reaction of Carbon with Metal Oxide (Understanding)

4. Everything is slowly oxidized, such as rust, wine making, food decay, breathing of people, animals and plants, etc.

5. Calcium oxide +H2O = = calcium hydroxide

Second, junior high school needs to know the endothermic reaction

1.C+CO2== high temperature ==2C0 (mastered)

2.CaCO3== high temperature = = Cao+CO2 = (understanding)

Third, junior high school students need to know the thermal effect in the process of dissolution.

1.When NaOH and concentrated sulfuric acid are dissolved in water, the solution temperature rises.

2. Ammonium salts such as 2. When NH4NO3 is dissolved, the temperature of the solution decreases.