暖手蛋為何會釋出熱?

其實呢個係化學反應黎

exothermic reaction

the heat pad inside the hand-warmer contains iron powder. by exposing the iron powder to air ,oxidation of iron occurs which is an exothermic reaction (=heat release)

4Fe(s) + 3O2(g) -----------> 2Fe2O3(s)

delta H negative


there are some way to increase the heat-released amount of heat pad
for example finely divded iron to increase the surface area to carry out the reaction
activated carbon to speed up the reaction
sodium chloride to speed up the reaction
..............

鐵粉在氧化過程中發出熱，跟活性碳產生化學作用。

佢既熱力係由蛋芯入面既鐵同氧氣產生化學作用

formula(如果我冇記錯):
4Fe + 3O2 -->2Fe2O3

氧化會產生熱力

其他成份(e.g.活性碳)
加速化學作用