Formats Heading 1 Arial 18pt Lab Results 1. Record the following lab results in

Question

Formats Heading 1 Arial 18pt Lab Results 1. Record the following lab results in the table below. volume of cold waterIn the calorimeter Initialtemperature of the cod water volume of hot water added to the calorimeter ature of the hot wate initial emper nnaltemperature in the calorimete Data Analysis 2. Calculate the calorimeter's constant. Experiment 2: Determine the Enthalpy of Neutralization of HCI by NH3 Lab Results 1. Record the following lab results in the table below. volume of HCl solution in theCalorimeter volume of NH3 solution added fina temperature in the calorimete NOTES Experiment 1: Find the Calorimeter Constant I took a constant temperature bath and turned it to 60 degrees C. Then I put 50 mL of water in an Erlenmeyer flask and placed it in the constant temperature bath. Next I stuck a thermometer in the erlenmeyer flaska and the temperature readout stead ly rose to 60.0C. Next, I took a calorimeter and added 50 mL of water to and stuck a thermometer in it. The temperature remained steady at 21.5 C After the water in the erlenmeyer flask reached 60.0C I poured the entire contents i nto the calorimeter for a total volume of 100mL of water in the calorimeter. The tem perature readout rose to 39.4C and remained steady Experiment 2: Determine the Enthalpy of Neutralization of HCl by NH3 I took a calorimeter and added 25 mL of 2 M Hydrochloric Acid for a total volume of 25mL. The temperature readout was steady at 21.5C Next, took 2 M Ammonia and added it to the existing solution of Hydrochloric Acid f or a combined total of 50 m of solution. The temperature readout rose to 33.2 C, th en started slowly dropping Experiment 3: Determine the Enthalpy of Dissolution of NH4Cl in Water I took a calorimeter and added 25 mL of water for a total volume of 25mL. The temp erature readout was steady at 21.5C After adding 5.000 g of ammonium chloride (NH4CI) and add to the calorimeter, the temperature dropped to 9.1 C

Explanation / Answer

Experiment 1 : Calorimeter constant

density of water = 1 g/ml, so volume of water = mass of water

mass of water (cold) = 50 g

Initial temperature of water (cold) = 21.5 oC

change in temperature (dT) = 39.4 - 21.5 = 17.9 oC

Specific heat of water Cp = 4.184 J/g.oC

Heat gained by cold water = mCpdT = 50 x 4.184 x 17.9 = 3744.68 J

mass of water (hot) = 50 g

Initial temperature of water (hot) = 60 oC

change in temperature (dT = 60 - 39.4 = 20.6 oC

Heat lost by hot water = mCpdT = 50 x 4.184 x 20.6 = 4309.52 J

Heat gained by calorimeter = 4309.52 - 3744.68 = 564.84 J

calorimeter constant = 564.84/17.9 = 31.55 J/oC

Experiment 2 : Enthalpy of neutralization of HCl with NH3

Total mass of solution = 50 ml x 1 g/ml = 50 g

specific heat of water = Cp = 4.184 J/g.oC

initial temperature = 21.5 oC

final temperature = 33.2 oC

change in temperature (dT) = 33.2 - 21.5 = 11.7 oC

Enthalpy of neutralization = mCpdT = 50 x 4.184 x 11.7 = 2447.64 J

Enthalpy per mole of H2O formed = 2.44764 kJ/2 M x 25 ml = 48.953 kJ/mol

Experiment 3 : ERnthakpy of dissolution of NH4Cl in water

mass of water + NH4Cl = 25 + 5 = 30 g

change in temperature (dT) = 9.1 - 21.5 = -12.4 oC

heat of dissolution = mCpdT = 30 x 4.184 x -12.4 = -1.556 kJ

heat of dissolution per mole of NH4Cl = 1.556 x 53.49/5 = -16.65 kJ/mol

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.