A science teacher brings a portable instant heating pad to show the class. The device is a vinyl bag containing a liquid solution of sodium acetate
and a small steel disc. When the teacher flexes the disc, the liquid in the bag crystallizes and the bag feels warm to the touch.
Steel disc-
Before: Vinyl bag contains
a liquid solution of sodium
acetate.
After: Flexing the steel
disc causes the sodium
acetate to crystallize.
How can students find out how much heat energy is released as the sodium acetate solution in the bag crystallizes?
A. Weigh the bag before and after it is activated.
B. Time how long it takes for the solution to completely crystallize after the bag is activated.
C. Use water displacement to measure the volume of the bag before and after it is activated.
D. Place the activated bag in 1000 mL of water and measure the change in the temperature of the water.

The solution of sodium acetate trihydrate energy released is 19.7 kJ/mole which is an endothermic process. The crystallization is exothermic.

What is crystallization?

Crystallization can be defined as the solidification of a liquid substance into a highly structured solid whose molecules are placed in a well-defined three dimensional crystal lattice.

A. Before weight: 280gm and after heating of pad, weight increases by 10-20gm approx (300gm).

B. It takes 12-20 minutes for the solution to completely crystallize after the bag is activated.

For more information regarding crystallization, visit:

https://brainly.com/question/4155452

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