Cold Pack And Exothermic Reaction Lab Report

Retrieved October 05, 2017, from http://chicagoacs.org/articles.php?id=183 3. Plop, Plop, Fizz Fast: The Effect of Temperature on Reaction Time. (2017, July 28). Retrieved October 05, 2017, from https://www.sciencebuddies.org/science-fair-projects/project-ideas/Chem_p027/chemistry/alka-seltzer-effect-of-temperature-on-reaction-time#background 4.

In the second portion of this experiment we will keep the temperature constant and divide the ½ tablet of Alka- Seltzer into 2 pieces ,3 pieces and an unbroken ½ tablet. It is my belief that Alka-Seltzer

= -455.9 joules/g. This solution reaction is exothermic; because temperature was increased meaning heat was released. In the last part of the experiment, neutralization reaction was investigated. NaOH(aq) + HCl(aq)

Discussion: 1. In this graph the temperature that the beaker started of at was at -2 degrees because it had just came out of the freezer for 48 hours. There were times where the graph plateaued out and times when the graph had an incline. There was an incline when the results reached 42 degrees until it reached 90 degrees. The graph plateaued out when the temperature reached 26 degrees and stayed on for one minute (4mins to 5mins).

Introduction The intent of this experiment is to understand how hot and cold water interact with each other by combining clear hot water and black ice cold water. I hope to learn more about how hot and cold water interact with each other. As of now, I know that cold water is denser than hot water. Knowing this I formed my hypothesis.

TAS tubes we used TAS2R38F and TAS2R38R. Each primer is complementary to one strand of the DNA, and these primers allowed for instant DNA amplification of a certain DNA sequence at a specific site. Each student then added their cheek cells to their respective tubes, and then they would be centrifuged and then placed in a thermocycler. The thermocycler had pre-programmed temperature to denature, anneal, and synthesize the DNA. After completing the PCR reactions, we placed our tubes into a freezer(Leight and McAllister 2017). Every student grabbed their specific tube and let it thaw out.

Due to this, a great amount of heat was lost to the environment since the apparatus was not in enclosed in order to prevent heat loss. A design including a more precise and calculated apparatus would have potentially improved the accuracy of the experiment. Overall, an improvement of the design of the calorimeter and a more standardized experiment would have led to more realistic and percise results. The extension of this experiment could further involve the analyzation on the energy storage of lipids and carbohydrates.

Carefully, 15-20g of pre-cooled cyclohexane was poured into the freezing-point tube, the tube recorked, and the whole thing was reweighed, to find the exact mass of the cyclohexane. The dry thermistor and stirrer were inserted into the FP tube, ensuring they were immersed in the liquid. A large beaker was filled with ice and water, which the FP tube was placed into. The cooling curve was determined by recording the temperature at regular time intervals (every fifteen seconds) as the cyclohexane cooled, until the temperature became constant. The cyclohexane was stirred continuously.

Our objective was to pick the best chemical to be used in a hand warm. This chemical had to be cheap, relatively safe, and must raise the temperature by 20oC and no more. We add 6 different chemicals to water we record the inshell temperature and then add one a the 6 chemicals to the water and record the temperature change of the water. We also add cold water hot water together to find how much heat would escape the calorimeter. We found that the calorimeter absorbed 71.1J/oC. Then this information to calculate the energy that was released by all of the chemical reaction.

Chapter -1: OBJECTIVE the more general When designing a small temperature control system, the best choice for a refrigerator/heater element is often a thermoelectric cooler (TEC). The operation of these devices is based on the Peltier effect, which was discovered in 1834 by Jean Peltier. When an electrical current is passed through the junction of two dissimilar metals (Figure 1), heat is also transferred across the junction. To pump heat, a thermoelectric cooler can require a significant amount of power, with typical drive voltages ranging from 2V to 12V and typical drive currents ranging from a fraction of an ampere to tens of amperes.

This was displayed in table 1, where the final temperatures of the water are lower compared to the initial temperatures, showing that the potassium chloride took heat energy away from the 20 mL of water. Endothermic deicers work slower than exothermic deicers, because endothermic deicers require warmer temperatures to dissolve, which makes them inferior when environmental temperatures are very low. Additionally, exothermic deicers will release energy as heat when the compounds dissociate, consequently, melting snow and ice faster.4 Furthermore, when comparing the enthalpy of dissolution of potassium chloride to magnesium chlorides value of -270, the most exothermic value in table 2, potassium chloride is shown to be a significantly worse deicer. Magnesium chloride being notably exothermic means that the compound can dissolve at low temperatures and releases copious amounts of heat

For example, if the water volume is decided to stay constant as 1000mL for every trial, one can always first fill the tub with 400mL of tap water and then add ice or hot water to manipulate the temperature. In addition, the process can be facilitated by marking 1000mL on the plastic tub since the same tub will be used throughout the

Most people can guess that the handwarmers we use so often, especially during the colder seasons, is warm as a result of chemical reactions. How is it, however, that with a simple shake, it awakens the chemicals to suddenly react with each other? Which chemicals are the best at giving off heat during reaction? How do they actually work? Our recent study of thermodynamics has led me to become curious about those little helpful packages of warmth.

It is a subcategory of the standard enthalpy of reaction and defined as the energy released with the formation of 1 mole of water (Enthalpy of neutralization, 2018). Standard enthalpy of reaction is the enthalpy change that occurs in a system when matter is transformed by a chemical reaction. All products and reactants must be in their standard state (Standard enthalpy of reaction, 2017). The standard enthalpy change can be found by dividing the heat released during the reaction by the number of moles involved in the reaction (Enthalpy of neutralization,

As aforementioned thermodynamics deals with a lot of forms of energy, so in this case we would be using chemical. The goal of this project is to observe the thermodynamic process whi8ch will ultimately lead to the creation of ice cream. In this group assignment we are conducted to test how thermodynamic