Answer Happy

1. Gravimetric Determination of Kn Mass of Evap Dish (tare) 20.9522 Calculated Values Mass of Evap Dish (gross) 215764 record cach value until two are 21.5757 21.5770 21.5766 within 2 mg of one another Avg Final Mass (gross) Net mass of NH.NO, Moles of NH.NO, Molarity of NH.NO,
3. Determination of the Heat of Solution of Ammonium Nitrate Room Temperature 23.4°C 2 Trial Number Mass of NH.NO 4.17689 3.94469 Moles of NH.NO Initial Temperature (T) 23.4°C 23.4°C 17.6°C T at time - 100 min (T) 634 min 17.8°C AT - T-T 9 water 9 cal 9 min ΔΗχολη Average AH goln
VE . RE WE F VET OM TE BE I Time: 06346273 min Temperature: 17589 LL M M DE DOWE w Temperature 175C 4,1768g WHY NO3 rmponia-TEC
4. Calculations 4.1 Gravimetric analysis of Ksp for ammonium nitrate. 4.1.1 Determine the mass of solid ammonium nitrate present in the saturated solution. Convert this into moles (FW NH.NO, is 80.06 g/mol). The concentration of ammonium nitrate in the saturated solution must be the number of moles you calculate divided by the volume in liters of the solution you removed (7.500 x 10-4 L). 4.1.2 The molarity of the ammonium nitrate must be the molarity of ammonium and nitrate in the solution. The Ksp is then the product of these two concentrations. I Determine a value for the Ksp of ammonium nitrate. 4.2 ISE analysis of Ksp for ammonium nitrate - OMITTED. Print
4.3 Determination of heat of solution from calorimeter data 4.3.1 You should have a value for T, and T for each of the calorimetry runs. From this determine AT which is T-T.. We will assume that the heat lost by the ammonium nitrate solution is the same as if it was lost by water and that the mass of the water is the same as the volume (density equal to one). Calculate the heat absorbed by the reaction using the s of water to be 4.184 J/g-°C, the density of water as 1.00 g/ml, and the ms of the calorimeter as being 10 J/°C. You should have a heat term for the water as well as the calorimeter as follows (note both of these q values should be negative): 4 water -ms AT-(mass of water used) x 4.184 J/g-ºC x (Tp-T.) 9 calms AT - 101/°C x (Tf - T.) Determine the values for a water and 4 cal and enter this information into the table provided. 4.3.2 The heat lost by the water and the calorimeter plus the heat absorbed by the reaction is equal to zero: 9 total 0 - 9rxn+q water + 4 calorimeter This equation can be solved for the heat given off by the reaction: 9 rxn--9 water +- 4 calorimeter Calculate the value for a reaction and enter it into the table provided. The enthalpy change for the reaction is the heat given off divided by the number of moles of limiting reagent. Divide the rxn by the moles of material used and enter this value as the AH soln in the table (note that the q rxn and the AHsoln will both be positive) 4.3.3 'You should have two values for the enthalpy solution from the two trials so determine the average value and record this in the table provided. 4.4 Determination and comparison of thermodynamic values 4.4.1 The relevant equations are: AG - SH-TAS and AG -RTINK. You should also know how to calculate AH, AG and AS values from data as described in Appendix section of the Gilbert text. 4.4.2 The data for ammonium nitrate as well as for the aqueous ammonium ion and nitrate ion are given below. Substance ΔΗ, AG AS Ammonium Nitrate (NH4NOX) -365.6 kJ/mol -184.0 kJ/mol 151.1 J/mol-K Ammonium ion (NH) - 132.8 kJ/mol -79.5 kJ/mol 112.8 J/mol-K Nitrate ion(NO) -206.6 kJ/mol -110,5 kJ/mol 146,4 J/mol-K From this data determine the standard values of AH, AG and As for ammonium nitrate solid becoming ammonium nitrate solution. 4.4.3 From the molarity of the ammonium and nitrate ions determined from the gravimetric analysis calculate the value of the K, for ammonium nitrate
4.4.4 From the relationship between the standard Gibbs Free Energy and the equilibrium constant calculate a value for the standard Gibbs Free Energy using the Kop value in 4.4.3. 4.4. From the calculated AG value and the average AH value calculate the AS value for this reaction using the gravimetric value of AGº. 4.4.6 Determine the standard reference values for AH”, AS, and AG from the data give on page 6 or from the Appendix in the Gilbert 6th Ed. text. 4.4.7 Determine the percent error for AH®, AS, and AG° between the experimental (AH° from the average heat of solution value, AGⓇ from the equilibrium constant, and AS from 4.4.5 above) and the reference values.