I5-41
Aid a discussion of entropy.
31.5 grams of barium hydroxide and 15.2 grams of ammonium thiocyanate, both solid powders initially at room temperature, are mixed. As they are stirred using the digital thermometer probe a chemical reaction occurs, producing water with barium cyanate and ammonium, both of which are soluble in the water. The solution becomes very cold, and can freeze a wettened wooden block to the bottom of the beaker.

This experiment can be described in terms of entropy using two approaches: (1) As the mixture cools, it must become a liquid, increasing its disorder so that entropy will increase, or (2) The tendency toward disorder drives the reaction, creating the liquid reaction product.

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