Explain the observed temperature change upon mixing ethanol and water
When ethanol and water are mixed together, the temperature of the mixture typically decreases. This phenomenon is known as an endothermic reaction.
The reason for the temperature decrease is due to the intermolecular forces between the ethanol molecules and water molecules. Ethanol molecules are polar, meaning they have a slightly positive and negative end, while water molecules are also polar. When the two liquids are mixed together, the ethanol molecules and water molecules are attracted to each other through hydrogen bonding. This interaction requires energy to occur, and as a result, the surrounding environment loses heat, causing the temperature to decrease.
Additionally, the mixing of ethanol and water can also lead to a decrease in entropy, as the molecules are becoming more ordered when they bond together. This further contributes to the decrease in temperature.
Overall, the observed temperature change upon mixing ethanol and water is a result of the energy required for the intermolecular forces to form between the molecules, leading to an endothermic reaction and a decrease in temperature.