Chem152_Thermo1_Report_finito

# Chem152_Thermo1_Report_finito - Name: Efrain Montes Quiz...

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Unformatted text preview: Name: Efrain Montes Quiz Section: AT ID Num 1131865 Lab Partner: Austin Miner Total Points = 60 pts (5 notebook, 55 template) PURPOSE AND METHOD DATA AND CALCULATIONS A: HEAT CAPACITY OF THE CALORIMETER Run 1 Run 2 Run 3 Voltage, V (J/C) 4.6 4.6 4.6 Cur ent, A (C/s) 2.14 2.15 2.15 Time (s) 144 150 146 24.5 24.2 24.7 28.7 28.4 28.9 *Eletrical power input into calorimeter (q), J 1418 1484 1444 335.5 350.9 342.4 342 Standard Dev 8 Help In Excel type "=average(range of values)" Instead of entering a range, just click at one end of the values and drag m ouse to the other end. For standard deviation, in Excel type "=stdev(range of values)". B: HEAT OF FUSION OF ICE Run 1 Run 2 342 342 181.28 181.23 187.224 187.245 Mass of ice, g 5.947 6.018 24.4 24.1 0.0 0.0 18.5 18-5.9-6.1 * (a) Heat lost by calorimeter (q cal in J) 2,018 2,086-24.4-24.1 4.184 4.184 * (b)-607-607 *(c) 441 447 AVERAGE 444J/g Standard Dev 4J/g C: HEAT OF NEUTRALIZATION 2.5 pts HCl + NaOH NaOH Concentration 0.50 M Volume Used 40mL HCl Concentration 0.50 M Volume Used 40mL Run 1 Run 2 342 342 22.6 22.8 22.6 22.8 22.6 22.8 26.5 27.4 ∆T, ˚C 3.9 4.6 * (a) 0.020 0.020 * (b) q (J) (magnitude of heat gained/lost ) 1,334 1,573 * (c) ∆H (neut) (kJ/mol)-66.7-78.7 Average, ∆H (neut), kJ/mol-72.7 6 pts Standard Dev 8.5 Acetic acid + NaOH NaOH Concentration 0.50 M Volume Used 40 mL Acetic acid Concentration 0.50 M Volume Used 40 mL Run 1 Run 2 342 342 22.5 22.9 22.5 22.9 22.5 22.9 26.8 26.9 ∆T, ˚C 4.3 4.0 0.020 0.020 q (J) (magnitude of heat gained/lost ) 1,471 1,368 ∆H (neut) (kJ/mol)-73.5-68.4 Average, ∆H (neut), kJ/mol-71.0 Standard Dev 3.6 D: ENTHALPY OF HYDRATION OF MAGNESIUM SULFATE 2.5 pts Run 1 Run 2 342 342 4.524 4.264 * (a) 0.03758 0.03542 24.7 24.7 32.8 35.1 ∆T, ˚C 8.1 10.4 * (b) q (J) (magnitude of heat gained/lost ) 2,770 3,557 * (c) ∆H (Solution) (kJ/mol)-73.7-100.4 Average, ∆H (Solution), kJ/mol-87.1 5 pts Standard Dev 18.9 Run 1 Run 2 342 342 10.232 10.159 0.041513 0.041217 24.6 24.2 22.8 22.5 ∆T, ˚C-1.8-1.7 q (J) (magnitude of heat gained/lost )-616-581 ∆H (Solution) (kJ/mol)-14.8-14.1 Average, ∆H (Solution), kJ/mol-14.5 Standard Dev 0.5 * (d) Enthalpy of Hydration 101.5 kJ/mol RESULTS AND DISCUSSION Hint: Use heat capacity of water 4 338 * 171 50 mL (or 50 g) of water instead? Initial temperature, o C Final temperature, o C *Calorimeter Constant, C cal, J/ o C Average, C cal C cal (Average), J/ o C Mass of calorimeter, stir bar and water, g Mass of calorimeter, stir bar, and water + mass of added ice (or melted ice), g Temperature of calorimeter before ice addition, o C Temperature of ice before addition to the calorimeter, o C Temp. of the calorimeter after addition and melting of the ice, o C ∆ T cal ∆Τ water from ice Specific heat of water, J/g....
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## This note was uploaded on 02/17/2012 for the course CHEM 152A taught by Professor Chiu during the Winter '12 term at University of Washington.

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