How do instant icepacks work in relation to specific heat capacity?
1 Answer
- Minimum temperature reached: Lower for those of higher heat capacity;
- Initial rate of heat exchange: Lower for those of higher heat capacity.
Explanation:
Instant ice packs typically contain water and anhydrous ammonia nitrate
- the number of moles of solid dissolved, and
- the final concentration of the solution.
By the definition of specific heat capacity, the temperature change
Assuming constant initial temperature, a solvent of higher standard heat capacity will lead to a lower
The rate of heat exchange between two bodies is directly related to the difference in their temperatures.[2]
Thus, increasing the standard heat capacity hence the deviation from the room temperature will speed up heat absorption. As a result, ice packs with larger heat capacity (e.g., containing more water) last longer than those with lower heat capacity- given that they are capable of absorbing the same amount of heat.
References
[1] Wikipedia contributors. "Ice pack." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 18 Apr. 2018. Web. 2 May. 2018.
[2] “Rates of Heat Transfer.” The Physics Classroom, www.physicsclassroom.com/class/thermalP/Lesson-1/Rates-of-Heat-Transfer