Trials Data and calculations Mass of potassium nitrate: 20.088 Moles of potassium nitrate: 0.1924_mol Trial 1 Trial 2 Tr
Posted: Mon May 02, 2022 7:59 pm
Trials Data and calculations Mass of potassium nitrate: 20.088 Moles of potassium nitrate: 0.1924_mol Trial 1 Trial 2 Trial 3 Trial 14 Total volume (ml.) 25.3 30.00 34.7 Temperature of crystal formation (C) 48. 159.4 53.4 49.0 Trial 1 Trial 2 Trial #3 Trial 14 [KNO.I.M 39.844.8 120.00 Trial 5 KIKINO, Ink Temperature, K T!,K 343 34 332 4326.4 322 321 | 0.0024 3x10 3 3.06 107 3.180 3.11810² AG, J/mol Mean value of AG: KJ/mol Plot a graph of ink, vs. T' and estimate the slope and intercept. Your instructor may have you use a spreadsheet or a graphing calculator instead of graphing by hand. Slope: y-intercept: ΔΗ: AS: - 193-
Post-lab questions 1. Is dissolving KNO, in water an exothermic or endothermie? Briefly explain. 2. Were the entropy changes positive or negative? 3. Was dissolving KNO, spontaneous for every trial? Briefly comment. (Hint: think about AG) 4. A small number of compounds become more soluble at lower temperatures. Predict the sign of AH, AS, and AG for such a substance. - 195 -
Post-lab questions 1. Is dissolving KNO, in water an exothermic or endothermie? Briefly explain. 2. Were the entropy changes positive or negative? 3. Was dissolving KNO, spontaneous for every trial? Briefly comment. (Hint: think about AG) 4. A small number of compounds become more soluble at lower temperatures. Predict the sign of AH, AS, and AG for such a substance. - 195 -