Introduction:
In day-to-day life it is very common to experience phenomenon’s involving heat or heat transfer. For instance, hand warmers used to warm fingers while skiing and ice packs used to reduce swelling of an injury, involve heat exchange. What is responsible for this heat exchange? Looking at thermochemistry may give an explanation. Thermochemistry is a branch of chemistry focusing on heat. Specifically, it studies heat released or absorbed in a chemical reaction. 1 Reactions releasing heat are referred to as exothermic, while reactions absorbing heat are endothermic. 2
Calorimetry, used in thermochemistry is, “the science associated with determining the changes in energy of a system by measuring the heat exchanged with the surroundings.” 3 Calorimetry is carried out with calorimeters, which measure heat transfer. 3 This experiment uses two types of calorimeters; a homemade, Styrofoam calorimeter, and a market brand calorimeter. This Styrofoam calorimeter is a less complex version of the market calorimeter and is used in some schools to save money. 4 Necessary features for a calorimeter include good insulation and little to no holes reducing heat loss to the surroundings.
The goal for this experiment is to assess the usefulness of a homemade, Styrofoam calorimeter in comparison to a market brand calorimeter when studying the energy and heat associated with chemical reactions such as acid-base and redox reactions. 4
Calorimetry is the science of measuring the change in heat absorbed or released during a chemical reaction. The change in heat can tell us if the reaction is either exothermic - it released or heat into surroundings, or endothermic - it absorbed heat from surroundings. The device used to measure calorimetry is a calorimeter. A calorimeter can range from very expensive lab ones to coffee styrofoam cups but they are all tightly sealed in order to prevent heat from escaping.
Heat: The amount of energy associated with the movement of atoms and molecules in matter.
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To learn about the laws of thermodynamics and use thermodynamics formulas to calculate heat transfer
In part I, the ΔH of each individual reaction was obtained by performing each reaction inside a calorimeter. Temperature probes were inserted in the calorimeter and ΔT was measured. By using the equation q = Msol’n x Cp x ΔT + Ccal x ΔT, the heat absorbed by the surroundings, q, was obtained for each reaction. The negatives of these values, or heat released by the
Exothermic reactions transfer energy to the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to become hotter. The temperature increase can be detected using a thermometer. Some examples of exothermic reactions are:
Heat is a form of energy, sometimes called thermal energy, which can pass spontaneously from an object at a high temperature to an object at a lower temperature. If the two objects are in contact, they will, given sufficient time, both reach the same temperature. Heat always travels from hot to cold objects and two objects will reach an equilibrium temperature. Heat flow is commonly measured in a device called a calorimeter, an insulating container that minimizes heat exchange between its contents and the surrounding. Heat flow in a device called a calorimeter. In this experiment, we should find the heat capacity of the
To improve the experiment, the methodology could be improved by having an efficient calorimeter to retain as much heat as possible, rather than just a tin can. Additionally, more trials for each of the experiments could be conducted to ensure correct and precise data is collected to determine more accurate conclusions.
The lab used methods of calorimetry in order to measure the temperature change of reactions and calculate the changes in
Thermal energy is the energy a substance or system has related to its temperature. This means the energy of moving or vibrating molecules. Atoms and molecules are always in motion. Generally the motion of thermal energy cannot be seen, but instead the effects it has on the substance can be seen or felt. Thermal energy can have several different uses. It can be used to heat homes, cook food, and generate electricity.
We will be using 6 different fuels to heat up 100ml of water, and find out the changes of the temperature. We will measure the temperatures of the water before and after the experiment. We will burn heat the water for exactly 2 minutes, and check the changes in temperature. The change in temperature will allow us to work out the energy given off the fuel by using this formula:
Heat is a form of energy that is transferred between two substances at different temperatures. The flow of the energy is from the object of higher temperature to the object of lower temperature. The heat is measured in units of energy, usually calories or joules. Temperature on the other hand, is how cold or hot an object is. The temperature is the average kinetic energy per molecule of a substance. This is measured in degrees on the Celsius or Fahrenheit or in Kelvins.
Purpose: To measure the heats of reaction for three related exothermic reactions and to verify Hess’s Law of Heat Summation.
Purpose: This lab taught procedures for determining heat of capacity of a calorimeter and measuring enthalpy of change for three reactions. It also enforced methods of analyzing data obtained through experimentation and calculating enthalpy. These procedures are used in the branch of thermodynamics known as thermochemistry which is the study of energy changes that accompany chemical reactions. Concepts from this lab can be used to determine the potential energy of a chemical reaction. Much of the energy people depend on comes from chemical reactions. For example, energy can be obtained by burning fuel, metabolizing of food or discharging a batter.
Rinse the thermometer with tap water and dry. Insert the thermometer in the calorimeters top and measure the initial temperature of the base 28.2∘C