Postlab Report for Colligative Properties

Postlab Report for Colligative Properties - Postlab Report...

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Postlab Report for Colligative Properties Chemistry 112 Lab Section 005 October 14, 2014 A. The research questions for this lab are: 1. What is the % dissolved solids in my potato? 2. What is the freezing temperature for pure lauric acid? 3. What is the MM of the unknown organic acid? B. Observations and Results. Tables Table 1. Osmosis Demonstrated by Changes in Potato Mass. Solvent Initial mass of potato (g) Final mass of potato (g) % Change in mass of potato (%) Direction of solvent flow (into or out of potato) Distilled water 24.100 24.720 2.5726 Into potato 9% Glucose 11.787 11.871 0.71265 Into potato 17% Glucose 28.055 27.261 -2.8302 Out of potato Calculations for table 1: % Change in mass of potato: Distilled water potato: 24.720 24.100 24.100 100 = 2.5726 9% Glucose potato: 11.871 11.787 11.787 100 = 0.71265 17% Glucose potato: 27.261 28.055 28.055 100 =− 2.8302 Table 2. Summary of Data & Calculations to Determine the MM of the Unknown Solute. Mass of lauric acid (g) 8.016 Mass of unknown organic acid (g) 1.005 Freezing temperature of pure lauric acid (°C) 44.0 Freezing point of the unknown-lauric acid mixture (°C) 41.0 Freezing point depression, ΔT (°C) 3.0 Molality (m) 0.77 Moles of unknown (mol) 0.0062 Molecular mass (MM) of unknown (g/mol) 1.6 x 10 2 Calculations for table 2 are on the attached data analysis. C. Complete claims for each of the research questions above.
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1. The % dissolved solids in my potato is 9.148 %. 2. The freezing temperature for pure lauric acid is 44.0 °C. 3. The MM of the unknown organic acid is 1.6 x 10 2 g/mol. D. Evidence Compose and attach a statement of the evidence you have to support each of the claims you made in Section C. You will need to describe some theoretical background about osmosis and freezing point depression. Specifically using your data, (you must use actual numbers and results from your experiment) explain why your claims are correct. You may refer to other sections of
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  • Spring '08
  • Chemistry, Freezing-point depression, Lauric acid, pure lauric acid

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