Atletas que sofrem problemas musculares durante competições podem utilizar bolsas instantâneas quentes
ou frias como dispositivos para primeiros socorros. Esses dispositivos funcionam mediante reações exo ou
endotérmicas. Normalmente são constituídas por uma bolsa de plástico que contém água em uma seção e
uma substância química seca em outra. Ao golpear a bolsa, a seção contendo água se rompe e a temperatura
aumenta ou diminui dependendo de a dissolução da substância ser exo ou endotérmica. Em geral, para
compressas quentes usa-se cloreto de cálcio ou sulfato de magnésio, e, para compressas frias, nitrato de
amônio.
Peruzzo, F. M.; Canto, E. L. Química na abordagem do cotidiano. 5ª. Ed. São Paulo: Moderna, 2009.
As equações representativas das reações são:
![](data:image/png;base64,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)
Adicionando-se 40 g de CaCl2
a 100 mL de água a 20°C, a temperatura da água aumenta de 20° C para 90°C.
Adicionando-se 30 g de NH4
NO3 a 100 mL de água a 20°C, a temperatura da água diminui de 20° C para 0°C. Tais bolsas
atuam por 20 minutos, aproximadamente.
Atletas que sofrem problemas musculares durante competições podem utilizar bolsas instantâneas quentes ou frias como dispositivos para primeiros socorros. Esses dispositivos funcionam mediante reações exo ou endotérmicas. Normalmente são constituídas por uma bolsa de plástico que contém água em uma seção e uma substância química seca em outra. Ao golpear a bolsa, a seção contendo água se rompe e a temperatura aumenta ou diminui dependendo de a dissolução da substância ser exo ou endotérmica. Em geral, para compressas quentes usa-se cloreto de cálcio ou sulfato de magnésio, e, para compressas frias, nitrato de amônio.
Peruzzo, F. M.; Canto, E. L. Química na abordagem do cotidiano. 5ª. Ed. São Paulo: Moderna, 2009.
As equações representativas das reações são:
Adicionando-se 40 g de CaCl2
a 100 mL de água a 20°C, a temperatura da água aumenta de 20° C para 90°C.
Adicionando-se 30 g de NH4
NO3 a 100 mL de água a 20°C, a temperatura da água diminui de 20° C para 0°C. Tais bolsas
atuam por 20 minutos, aproximadamente.