Chemical reactions can be categorized based on the release or absorption of energy. For instance, chemical reactions that release energy are known as exothermic reactions and have a positive change in enthalpy. Moreover, chemical reactions that absorb energy are endothermic, which have a negative change in enthalpy. Since the energy released is usually heat, keeping track of the heat flow in reactions will help determine the change in enthalpy of a reaction. Observing the measurement of heat changes is known as calorimetry; hence, in this lab a calorimeter was used to measure the changes in enthalpy. A calorimeter is well-designed when it is well insulated from the environment so there could be minimal to no heat change between the system and
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In this lab, a probe was connected to a MeasureNet device, in which it recorded the change in temperature as a function over time. The data for each part was then saved under separate files on an online data storage program that could be accessed later.
The overall goal of the lab was to measure and calculate the change in enthalpy by using a calorimeter to measure temperature changes within the Styrofoam cup system. In parts 1 and 4, the goal was to measure the enthalpy change of acid-based chemical reactions; part 1 reacted NaOH with HCl and part 2 reacted KOH and HCl. In parts 2, 3, and 5, 2.0 M of KOH, HCl, and NaOH were each separately diluted with water, respectively. After collecting the data, the goal of the lab was to then calculate the enthalpy change by using linear regression models on Excel and the appropriate equations relating to enthalpy …show more content…
In part 1, the strong base, NaOH, reacts with the strong acid, HCl, to produce a salt (NaCl) and water (H2O). As the molarity of both the bases and the acid was 2.0 M and equal volumes (10.0 mL) were used for each, mixing them caused a neutralization reaction where the sultion was neither acidic or basic. However, the most interesting trend was the fact that when sodium displaced hydrogen, there was a release of energy (heat) from breaking their respective bonds, and was absorbed by the water. In a similar manner, the products of reactinf KOH and were a salt (KCl) and water (H2O), in which energy (heat) is released when potassium displaces hydrogen and is then absorbed by the water. This can also be seen the changes in enthalpy of the acid-base reactions: NaOH and HCl had an enthalpy change of H = 347466.132 J/mol, while KOH and HCl had an enthalpy change of H = 3475317.694 J/mol. Therefore, the increase in temperature for acid-base reactions comes from water absorbing the heat that is released by the neutralization of the acid and base, and are ultimately exothermic
In this lab, a probe was connected to a MeasureNet device, in which it recorded the change in temperature as a function over time. The data for each part was then saved under separate files on an online data storage program that could be accessed later.
The overall goal of the lab was to measure and calculate the change in enthalpy by using a calorimeter to measure temperature changes within the Styrofoam cup system. In parts 1 and 4, the goal was to measure the enthalpy change of acid-based chemical reactions; part 1 reacted NaOH with HCl and part 2 reacted KOH and HCl. In parts 2, 3, and 5, 2.0 M of KOH, HCl, and NaOH were each separately diluted with water, respectively. After collecting the data, the goal of the lab was to then calculate the enthalpy change by using linear regression models on Excel and the appropriate equations relating to enthalpy …show more content…
In part 1, the strong base, NaOH, reacts with the strong acid, HCl, to produce a salt (NaCl) and water (H2O). As the molarity of both the bases and the acid was 2.0 M and equal volumes (10.0 mL) were used for each, mixing them caused a neutralization reaction where the sultion was neither acidic or basic. However, the most interesting trend was the fact that when sodium displaced hydrogen, there was a release of energy (heat) from breaking their respective bonds, and was absorbed by the water. In a similar manner, the products of reactinf KOH and were a salt (KCl) and water (H2O), in which energy (heat) is released when potassium displaces hydrogen and is then absorbed by the water. This can also be seen the changes in enthalpy of the acid-base reactions: NaOH and HCl had an enthalpy change of H = 347466.132 J/mol, while KOH and HCl had an enthalpy change of H = 3475317.694 J/mol. Therefore, the increase in temperature for acid-base reactions comes from water absorbing the heat that is released by the neutralization of the acid and base, and are ultimately exothermic