What happens to the temperature if different volumes of water set at different temperatures are mixed together? They will reach thermal equilibrium and their volume will be the sum of the two volumes.

Independent Variable: Temperature of the two substances alone. Dependent Variable: The volume/temperature of the two substances mixed together. Constants: The water that is poured into the other one when mixed. EX: hot into cold at all times Levels 80 mL hot and 50 mL cold Repeated Trials 1 trial

1. Measure 50 mL of cold water from the class ice bucket and pour it into a styrofoam cup. 2. Measure 80 mL of water from the sink and put it in a beaker. 3. Heat the beaker on a hot plate until it reaches around degrees Celsius. 4. Using a pair of beaker tongs, pour the water into a styrofoam cup. 5. Take the final temperature of the hot water. 6. Mix the two cups of water by pouring one cup into the other. 7. Put the temperature, in the cup of the mixed waters. Sensor and record the temperature every 10 seconds until the temperature stops rising and the mixed water reaches thermal equilibrium.

1. Hot plate, Beaker of water to be heated 2. Laptop, beaker of cold water, beaker of hot water, temperature sensor 3. Styrofoam cup of cold water, Styrofoam cup of hot water, temperature sensor

Time(seconds)Temperature(degrees Celsius)

Ever heard of thermal equilibrium? Well it’s the point at which two substances reach the same temperature. That is what happens when different volumes of water at different temperatures are mixed together. The independent variable is the volume and temperature of the two substances alone and the dependent variable is the volume and temperature of the substances mixed together. The relationship between them is that the two substances alone were two extremes and when they mixed together they balanced out. The central tendency of the data is the mean. This is because in order to find the temperature of the two substances mixed you have to add their original temperatures together and then divide by two, in other words find the mean. Due to the type of experiment it was and the results we got, we only did one trial.

The hypothesis that was stated was supported after completing this lab. As seen in the data table, each cup of water’s temperature varied greatly. The cold water was 5.0 degrees Celsius originally and the hot water was 84.4 degrees Celsius before the water was mixed. The mixed water reached an almost average temperature, 51.0 degrees Celsius. This relationship can also be seen in the graph, as the cold water’s bar has a very low bar, and the hot water has a high bar, and the mixed water’s bar is measure nearly between the two.

The most important concept demonstrated in this lab was thermal equilibrium. Thermal equilibrium is the state at which two substances reach the same temperature. For example, after the two cups of water were mixed, they eventually reached thermal equilibrium at 51.0 because their hot temperature and cold temperature leveled out to a median temperature. Thermal equilibrium can be seen a real world example where a soda is taken out of a refrigerator, and set on the room-temperature counter. Both the counter and bottle of soda will eventually reach a state of thermal equilibrium where they have the same temperature. Another term in Unit 10 that is evident in this lab is convection. When heat was being transferred between the two types of water in the cup, convection occurred. Convection is the transfer of heat by the movement of a liquid or gas. So, when the waters were mixed, and as they swirled together, heat transferred between them.