- #1
undertow
How can you tell when a reaction is endo or exothermic? From what i understand there are two ways to know:
1) if the enthaply(change in H) is greater than 0, it's endothermic. If the change in H is lower than 0, its exothermic.
2) Also,when the chemical bonds of the reactant molecules are greater than the energy stored in the chemical bonds of product molecules, the reaction is exothermic. In endothermic chemical reactions, the situation is reversed: more chemical energy is stored in the bonds of the product molecules than in the bonds of the reactant molecules.
However, when i see an example like the melting of ice this doesn't make sense:
H20(solid) ---> H20(liquid) Enthalpy= +6.01 kJ
The enthalpy is greater than zero, so it would be an endothermic reaction. But doesn't the reactant, H20(s), have stronger bonds than the product, H20(g), making it a exothermic reaction? a solid has stronger bonds than a liquid. someone please explain
1) if the enthaply(change in H) is greater than 0, it's endothermic. If the change in H is lower than 0, its exothermic.
2) Also,when the chemical bonds of the reactant molecules are greater than the energy stored in the chemical bonds of product molecules, the reaction is exothermic. In endothermic chemical reactions, the situation is reversed: more chemical energy is stored in the bonds of the product molecules than in the bonds of the reactant molecules.
However, when i see an example like the melting of ice this doesn't make sense:
H20(solid) ---> H20(liquid) Enthalpy= +6.01 kJ
The enthalpy is greater than zero, so it would be an endothermic reaction. But doesn't the reactant, H20(s), have stronger bonds than the product, H20(g), making it a exothermic reaction? a solid has stronger bonds than a liquid. someone please explain