Hello! I'm in need of some help understanding how to do these concept calculations. DATA Trial 1: Mg Trial 2: MgO Trial 3: Mg Trial 4: MgO Mass of Mg/MgO 0.4119 g 0.9850 g 0.4014 g 1.0001 g Initial Temp in ℃ 22.3 ℃ 22.8 ℃ 22.7 ℃ 23.2 ℃ Final Temp in ℃ 41.4 ℃ 29.4 ℃ 40.9 ℃ 28.7 ℃ Change in Temp in ℃ 19.1 ℃ 6.6 ℃ 18.2 ℃ 5.5 ℃ 1 A) For each of your trials determine the heat liberated. Assume the HCI solution in the calorimeter has a density of 1.00 g/mL and that the calorimeter loses a negligible amount of heat. (The specific heat of the solution can be assumed to be the same as water, 4.184 J/g.℃.) q = (mass) × (specific heat) × (Δt)
Hello! I'm in need of some help understanding how to do these concept calculations.
| DATA | Trial 1: Mg | Trial 2: MgO | Trial 3: Mg | Trial 4: MgO |
| Mass of Mg/MgO | 0.4119 g | 0.9850 g | 0.4014 g | 1.0001 g |
| Initial Temp in ℃ | 22.3 ℃ | 22.8 ℃ | 22.7 ℃ | 23.2 ℃ |
| Final Temp in ℃ | 41.4 ℃ | 29.4 ℃ | 40.9 ℃ | 28.7 ℃ |
| Change in Temp in ℃ | 19.1 ℃ | 6.6 ℃ | 18.2 ℃ | 5.5 ℃ |
1 A) For each of your trials determine the heat liberated. Assume the HCI solution in the calorimeter has a density of 1.00 g/mL and that the calorimeter loses a negligible amount of heat. (The specific heat of the solution can be assumed to be the same as water, 4.184 J/g.℃.)
q = (mass) × (specific heat) × (Δt)
q = (kilojoules)
Trial 1: ________. Trial 2: ________. Trial 3: _________. Trial 4: _________.
1 B) Change each q to ΔH with the appropriate sign. Remember that enthalpy has been gained by the water, therefore, enthalpy has been lost by the reaction system.
ΔH = (kilojoules)
Trial 1: ________. Trial 2: ________. Trial 3: _________. Trial 4: _________.
1 C) Calculate the molar ΔH for each trial.
molar ΔH (kJ/mol)
Trial 1: ________. Trial 2: ________. Trial 3: _________. Trial 4: _________.
2) Write a balanced equation for the two reactions, Mg + HCI, and MgO with HCI.
3) Calculate the average molar ΔH for each of the reactions.
4) Use Hess's Law to determine the ΔH for the reaction: Mg (s) + 1/2 O2 (g) → MgO (s)
You will need to use the experimentally determined ΔH's and the standard heat of formation of water (1) to determine this.
5. Calculate the % error of your ΔH as compared to the textbook value for the heat of formation of MgO.
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