Experiment 1: Calorimetry
Experiment 1: Calorimetry
Nadya Patrica E. Sauza, Jelica D. Estacio
Institute of Chemistry, University of the Philippines, Diliman, Quezon City 1101 Philippines
Results and Discussion
Eight Styrofoam ball calorimeters were calibrated. Five milliliters of 1M hydrochloric acid (HCl) was reacted with 10 ml of 1M sodium hydroxide (NaOH) in each calorimeter. The temperature before and after the reaction were recorded; the change in temperature (∆T) was calculated by subtracting the initial temperature from the final temperature. The reaction was performed twice for every calorimeter.
The heat capacity (Ccal) of each calorimeter was calculated using the formula,
C_cal=(-〖∆H〗_rxn^o n_LR)/∆T [1]
where ∆Horxn is the total heat absorbed or evolved for every mole of reaction and nLR is the number of moles of the limiting reactant. The ∆Horxn used was -55.8kJ per mole of water while the nLR was 0.005 mole.
Table 1. Average Ccal from recorded ∆T values. Trial ∆T, (oC) Ccal, (J) Ave Ccal, (J)
1 1 2.2 126.82 202.91 2 1.0 279.00
2 1 3.0 93.00 108.50 2 2.3 124.00
3 1 0.5 558.00 558.00 2 0.5 558.00
4 1 2.0 139.50 244.13 2 0.8 348.75
5 1 3.0 93.00 81.38 2 4.0 69.75
6 1 2.0 139.50 209.25 2 1.0 279.00
7 1 2.5 111.60 111.60 2 2.5 111.60
8 1 3.0 93.00 116.25 2 2.0 139.50
Different heat capacities were calculated for each calorimeter (Table 1).
After calibration, a reaction was performed in a calorimeter by each pair. A total of eight reactions were observed by the whole class.
The temperature before and after the reaction were recorded. Then the change in temperature was calculated.
Each reaction was performed twice to produce two trials.
The experimental ∆Horxn for each reaction was solved using the formula,
〖∆H〗_rxn^o=(-C_cal ∆T)/n_LR [2]
where Ccal is the heat capacity previously calculated for each calorimeter. The percent error for each reaction was computed by comparing the computed experimental ∆Horxn to the
Nadya Patrica E. Sauza, Jelica D. Estacio
Institute of Chemistry, University of the Philippines, Diliman, Quezon City 1101 Philippines
Results and Discussion
Eight Styrofoam ball calorimeters were calibrated. Five milliliters of 1M hydrochloric acid (HCl) was reacted with 10 ml of 1M sodium hydroxide (NaOH) in each calorimeter. The temperature before and after the reaction were recorded; the change in temperature (∆T) was calculated by subtracting the initial temperature from the final temperature. The reaction was performed twice for every calorimeter.
The heat capacity (Ccal) of each calorimeter was calculated using the formula,
C_cal=(-〖∆H〗_rxn^o n_LR)/∆T [1]
where ∆Horxn is the total heat absorbed or evolved for every mole of reaction and nLR is the number of moles of the limiting reactant. The ∆Horxn used was -55.8kJ per mole of water while the nLR was 0.005 mole.
Table 1. Average Ccal from recorded ∆T values. Trial ∆T, (oC) Ccal, (J) Ave Ccal, (J)
1 1 2.2 126.82 202.91 2 1.0 279.00
2 1 3.0 93.00 108.50 2 2.3 124.00
3 1 0.5 558.00 558.00 2 0.5 558.00
4 1 2.0 139.50 244.13 2 0.8 348.75
5 1 3.0 93.00 81.38 2 4.0 69.75
6 1 2.0 139.50 209.25 2 1.0 279.00
7 1 2.5 111.60 111.60 2 2.5 111.60
8 1 3.0 93.00 116.25 2 2.0 139.50
Different heat capacities were calculated for each calorimeter (Table 1).
After calibration, a reaction was performed in a calorimeter by each pair. A total of eight reactions were observed by the whole class.
The temperature before and after the reaction were recorded. Then the change in temperature was calculated.
Each reaction was performed twice to produce two trials.
The experimental ∆Horxn for each reaction was solved using the formula,
〖∆H〗_rxn^o=(-C_cal ∆T)/n_LR [2]
where Ccal is the heat capacity previously calculated for each calorimeter. The percent error for each reaction was computed by comparing the computed experimental ∆Horxn to the
References: Petrucci, R.H.; Herring, F.G.; Madura, J.D.; Bissonnette, C. General Chemistry, 10th ed.; Pearson Education: Canada, 2011; Chapter 7.