Calorimetry Lab Report Summary

The purpose of this particular lab was to experiment and identify the chemical and physical changes throughout the experiment.

In order to measure the heats of reactions, add the reactants into the calorimeter and measure the difference between the initial and final temperature. The temperature difference helps us calculate the heat released or absorbed by the reaction. The equation for calorimetry is q=mc(ΔT). ΔT is the temperature change, m is the mass, c is the specific heat capacity of the solution, and q is the heat transfer. Given that the experiment is operated under constant pressure in the lab, the temperature change is due to the enthalpy of the reaction, therefore the heat of the reaction can be calculated.

The results showed the molarity of the NaOH solution. This experiment was completed twice and a new average molarity

11. The experiment was repeated three more times using different water temperatures (room temp water, cold temp water, hot temp water).

For q, you found how much heat was gained by the water so you know that same amount of heat was lost by the metal. Therefore, qmetal = -qwater. The mass of the sample was recorded from the baggie. The temperature change

The control experiment for this investigation will be the experimental setup of 5 trials using 5oC as the temperature. All the steps in the method will be followed.

The boiling point elevation constant for water that was experimentally determined in this analysis was 0.4396 °C/m, which was derived from the slope of the trend line in Figure 2. This is slightly lower than the constant provided in lecture of 0.51 °C/m. This could be due to further evaporation of water from the solutions tested via refractive index after the boiling temperature was recorded.

A higher volume of NaOH will result in more moles of NaOH being added to the HCl, which results in more HCl reacting. This makes the calculated molarity of the HCl be smaller than the actual molarity of the HCl.

In this experiment, we investigate the change in temperature caused by adding a chemical substance into the water and dissolving it. The results recorded in the table below show that our hypothesis is correct.

HCl is known as Hydrogen chloride in its gas state, but when in the presence of water, it is known as hydrochloric acid(PubChem). Hydrochloric acid is extremely corrosive and has uses in both laboratories and industrial settings(PubChem). This acid can cause short term complications such as irritation to the eyes and nose or it can leave long term effects like dermatitis and chronic bronchitis (PubChem). Sodium hydroxide is a base that neutralizes acids and when in liquid form it has a higher density than water (PubChem). The compound is used in various textile industries (PubChem). NaOH can be corrosive to metals and is toxic if ingested (PubChem).

Introduction: The theory behind this experiment is the heat of a reaction (∆E) plus the work (W) done by a reaction is equal to

3. Calculate the total heat released in each reaction, assuming that the specific heat of the solution is the same as for pure water (4.18J/gK). Use q=mcΔT. Show work here and record your answer in Data Table 2.

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.

To achieve this, the final value from each thermocouple was set to be equal to the warm water bath temperature (370C), and the initial reading was set equal to the ice water bath temperature. Thus, for each thermocouple an equation was obtained using the two points to convert voltage readings to temperature. An example of the calibration for one of the thermocouples is shown in Appendix II.

Introduction: Every chemical change is accompanied by a change in energy usually in the form of heat. If heat is evolved, the reaction is exothermic, and if heat is absorbed, the reaction is endothermic. The energy change of a reaction that occurs at constant pressure is called the heat of reaction or the enthalpy of reaction (ΔHr). This quantity of heat is measured experimentally by allowing the reaction to occur in a calorimeter. In this experiment you will determine the heat of neutralization when an acid and a base react to form 1 mole of water. In a perfect calorimeter, heat is exchanged only between the reaction and the calorimeters water. Technically, some heat may may be absorbed the calorimeter. All calorimeters exchange some heat with its environment. This amount of heat is called the calorimeters heat capacity (the amount of of heat required to raise its temperature 1∘Celsius). We are going to “pretend” that our calorimeter is the perfect calorimeter.