As heat is required to break chemical bonds, the reverse is true so that heat is released when chemical bonds are formed.These form very quickly when a hydrogen ion from water meets an OH- ion from sodium hydroxide. Bruce,I pondered for a while about the heat capacity of water and then remembered that water is famous for having a high heat capacity. Therefore when heat is generated from the new chemical bond of water with hydroxide, the water does not boil until it has reached its full capacity of heat.Dilute sodium hydroxide presumably has a lower heat capacity and will boil and splutter dangerously when water is added to it - making adding sodium hydroxide to water the favoured option. Careful with those lumps mind you!
Mixing Sodium Hydroxide and Water
in Large Format
Posted
Ramachandra,
As heat is required to break chemical bonds, the reverse is true so that heat is released when chemical bonds are formed.These form very quickly when a hydrogen ion from water meets an OH- ion from sodium hydroxide. Bruce,I pondered for a while about the heat capacity of water and then remembered that water is famous for having a high heat capacity. Therefore when heat is generated from the new chemical bond of water with hydroxide, the water does not boil until it has reached its full capacity of heat.Dilute sodium hydroxide presumably has a lower heat capacity and will boil and splutter dangerously when water is added to it - making adding sodium hydroxide to water the favoured option. Careful with those lumps mind you!