Barium Hydroxide and Ammonium Thiocyanate (Endothermic)
Embed This Widget
Add the script tag and a data attribute to embed this widget.
Embed via iframe for maximum compatibility.
<iframe src="https://chemfyi.com/iframe/entity//" width="420" height="400" frameborder="0" style="border:0;border-radius:10px;max-width:100%" loading="lazy"></iframe>
Paste this URL in WordPress, Medium, or any oEmbed-compatible platform.
https://chemfyi.com/entity//
Add a dynamic SVG badge to your README or docs.
[](https://chemfyi.com/entity//)
Use the native HTML custom element.
Ba(OH)2·8H2O + 2NH4SCN → Ba(SCN)2 + 2NH3 + 10H2O
Visão geral
This highly endothermic acid-base reaction absorbs so much heat that it can freeze water beneath the flask. Mixing barium hydroxide octahydrate with ammonium thiocyanate drops the temperature below -20 C. The ammonium ion acts as a weak acid donating protons to hydroxide.
Participantes
Exemplo do cotidiano
This is one of the most dramatic endothermic reaction demonstrations, where a wet board freezes to a beaker as the reaction proceeds.
Importância industrial
Esta reação é utilizada principalmente como demonstração pedagógica de processos endotérmicos e reações impulsionadas pela entropia, ilustrando o conceito termodinâmico de ΔG = ΔH - TΔS.
Propriedades
- Tipo
- Acid-Base
- Reversível
- Não
- Energia
- Endotérmico
- ΔH
- 170,0 kJ/mol