Entropy is the study of the disorder of reactions. Consider a deck of playing cards. If you buy a brand new deck, all of the cards are in four suits lined up in numerical sequence from Ace to King. A brand new deck of playing cards has order. If you were to take this deck of cards and throw all of them into the air, you would have disorder. You could pick up the cards, placing them back into suit and sequence. This action would once again give you order.
In this topic, you learned that reactions can either have a positive or negative change in entropy. Some reactions begin highly organized and become disorganized. Other reactions begin disorganized and end up with more organization.