Calorimetry
Experiment 1: Calorimetry
INTRODUCTION
In the calibration of the calorimeter, the net ionic equation used is H+(aq) + OH-(aq) H2O(l). The reaction released heat and is said to be exothermic. HCl is the limiting reactant of the reaction and o.oo5 moles of it was used. The heat generated by the reaction is 55.8 kJ. The sign of T of the reaction used for calibration is opposite to that of H. In the determination of heats of reaction, the reaction of 15 mL 1 M CuSO4 + 0.05 g Zn produced a net ionic equation of CuSO4 + Zn ZnSO4 + Cu. The limiting reactant of the reaction is Zn and 0.05 moles of it was used. The sign of T of the reaction used for calibration is opposite to that of H.
WORKING EQUATIONS:
H+(aq) + OH-(aq) H2O(l) Hrxn= -55.8 KJ/mol
Hrxn=qrxn / nLR qcal=CcalT qcal=-qrxn
Ccal=mass x specific heat
Hrxn=npHop - nr Hor qcal= [Ccal+ mass solid (ppt.) x specific heat of ppt.] x T
RESULTS AND DISCUSSION
The reaction of HCl and NaOH for calorimeter calibration brought about a 1°C change in temperature (from 29.5 °C to 30.5 °C). The results of the other groups’ calibration are found in TABLE A of the data sheet.
The displacement of one metal by another (1M CuSO4 and 0.5g Zn) resulted to an increase in the temperature of the system. The 30 °C temperature measured from 15 mL 1 M CuSO4 went up to 31.5 °C upon addition of a 0.05-gram Zinc dust. Therefore, it is an exothermic process. All other neutralizations and reactions in the experiment have negative enthalpy values, so they are also exothermic.
It is therefore concluded that the factors that determine the enthalpy values of reactions are the kinds of reaction that have occurred and the nature of reactants involved.
REFERENCES
[1] Silberberg, M.S. Principles of General Chemistry 2nd Ed. McGraw-Hill Companies Inc., New York.
2010
[2] Petrucci, R.H., Herring, F.G., Madura, J.D., Bissonnette, C. General Chemistry: Principles and
Modern
INTRODUCTION
In the calibration of the calorimeter, the net ionic equation used is H+(aq) + OH-(aq) H2O(l). The reaction released heat and is said to be exothermic. HCl is the limiting reactant of the reaction and o.oo5 moles of it was used. The heat generated by the reaction is 55.8 kJ. The sign of T of the reaction used for calibration is opposite to that of H. In the determination of heats of reaction, the reaction of 15 mL 1 M CuSO4 + 0.05 g Zn produced a net ionic equation of CuSO4 + Zn ZnSO4 + Cu. The limiting reactant of the reaction is Zn and 0.05 moles of it was used. The sign of T of the reaction used for calibration is opposite to that of H.
WORKING EQUATIONS:
H+(aq) + OH-(aq) H2O(l) Hrxn= -55.8 KJ/mol
Hrxn=qrxn / nLR qcal=CcalT qcal=-qrxn
Ccal=mass x specific heat
Hrxn=npHop - nr Hor qcal= [Ccal+ mass solid (ppt.) x specific heat of ppt.] x T
RESULTS AND DISCUSSION
The reaction of HCl and NaOH for calorimeter calibration brought about a 1°C change in temperature (from 29.5 °C to 30.5 °C). The results of the other groups’ calibration are found in TABLE A of the data sheet.
The displacement of one metal by another (1M CuSO4 and 0.5g Zn) resulted to an increase in the temperature of the system. The 30 °C temperature measured from 15 mL 1 M CuSO4 went up to 31.5 °C upon addition of a 0.05-gram Zinc dust. Therefore, it is an exothermic process. All other neutralizations and reactions in the experiment have negative enthalpy values, so they are also exothermic.
It is therefore concluded that the factors that determine the enthalpy values of reactions are the kinds of reaction that have occurred and the nature of reactants involved.
REFERENCES
[1] Silberberg, M.S. Principles of General Chemistry 2nd Ed. McGraw-Hill Companies Inc., New York.
2010
[2] Petrucci, R.H., Herring, F.G., Madura, J.D., Bissonnette, C. General Chemistry: Principles and
Modern
References: [1] Silberberg, M.S. Principles of General Chemistry 2nd Ed. McGraw-Hill Companies Inc., New York. 2010