Thermochemistry: An Ice Calorimeter Determination of Reaction Enthalpy
Thermochemistry: An Ice Calorimeter Determination of Reaction Enthalpy
Shannon Wedepohl
9/17/13
Abstract: During this experiment, an ice calorimeter was used to measure the change in volume in milliliters of magnesium metal and 1.00 M of sulfuric acid. We found the experimental molar enthalpy of the reaction to be ∆H = -370 ± 1 kJ/mol at 0˚C. This compares with an expected value of -466.9 kJ/mol at 25 ˚C, a 20.75% difference.
Introduction:
Many chemical reactions truly only encompass changes by exchanging heat energy, either by absorbing heat or releasing it. This heat is now energy lost or produced by the system as bonds and are formed or broken. The enthalpy change refers to the change in energy levels within a specific compound or reaction mixture. For example, the enthalpy change or a reaction can be positive, energy gained, or negative, energy lost. This can be used to measure the potential work energy that a system reaction may possess relative to other reactions and can provide data about the bonding strength of the products and reactants as well. If the product substances are given enough energy and experience stronger bonding forces than the reactants, the potential energy of the products is lower than that of the reactants, the reaction process will create a reaction process. It will release the energy difference as heat and/or work (potential energy), and this is called an exothermic reaction.
An example process would be:
Making ice cubes
Burning sugar
An example equation would be:
2H2 (g) + O2 (g) → 2H2O (g)
Methods:
Refer to lab manual.
Data:Ice Calorimeter Data
Before reaction During reaction After reaction
Time (s)
Pipet (mL)
360
0.681
390
0.602
420
0.528
450
0.465
480
0.413
510
0.368
540
0.325
570
0.293
600
0.258
630
0.235
Time (s)
Pipet (mL)
660
0.210
690
0.186
720
0.170
Time (s)
Pipet (mL)
0
0.850
30
0.845
60
0.840
90
0.834
Shannon Wedepohl
9/17/13
Abstract: During this experiment, an ice calorimeter was used to measure the change in volume in milliliters of magnesium metal and 1.00 M of sulfuric acid. We found the experimental molar enthalpy of the reaction to be ∆H = -370 ± 1 kJ/mol at 0˚C. This compares with an expected value of -466.9 kJ/mol at 25 ˚C, a 20.75% difference.
Introduction:
Many chemical reactions truly only encompass changes by exchanging heat energy, either by absorbing heat or releasing it. This heat is now energy lost or produced by the system as bonds and are formed or broken. The enthalpy change refers to the change in energy levels within a specific compound or reaction mixture. For example, the enthalpy change or a reaction can be positive, energy gained, or negative, energy lost. This can be used to measure the potential work energy that a system reaction may possess relative to other reactions and can provide data about the bonding strength of the products and reactants as well. If the product substances are given enough energy and experience stronger bonding forces than the reactants, the potential energy of the products is lower than that of the reactants, the reaction process will create a reaction process. It will release the energy difference as heat and/or work (potential energy), and this is called an exothermic reaction.
An example process would be:
Making ice cubes
Burning sugar
An example equation would be:
2H2 (g) + O2 (g) → 2H2O (g)
Methods:
Refer to lab manual.
Data:Ice Calorimeter Data
Before reaction During reaction After reaction
Time (s)
Pipet (mL)
360
0.681
390
0.602
420
0.528
450
0.465
480
0.413
510
0.368
540
0.325
570
0.293
600
0.258
630
0.235
Time (s)
Pipet (mL)
660
0.210
690
0.186
720
0.170
Time (s)
Pipet (mL)
0
0.850
30
0.845
60
0.840
90
0.834