A 500 mL sample of a rubbing ethanol alcohol with unknown concentration was

# A 500 ml sample of a rubbing ethanol alcohol with

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11. A 50.0-mL sample of a rubbing ethanol alcohol with unknown concentration was distilled at 78.37 °C. If the volume of the collected ethanol is 27-mL and its percent recovery is 77.14%, what is the % volume of the rubbing alcohol? A.75% B.60% C.70% D.63% 12. Which of the following scenarios might result in an increase of the calculated percent recovery of the distillation set-up? 13. You challenge your lab partner that if he/she is unable to freeze a 2 mL substance in a test tube you labelled as water (K f = 1.86 °C/m), he/she will go out with you. An ice bath with a constant temperature of -3 °C is provided to conduct the experiment. Knowing about the concept of freezing point depression, you added 0.04 g of NaCl to the solution beforehand. Will your lab partner go out with you? (Assume ideal solution of NaCl) 14. A 0.075 g sample of calcium is reacted with excess hydrochloric acid at 22°C with an atmospheric pressure of 756 mmHg. The resulting gas was collected over water and was measured to be 48.50 mm. 1 A. Write the balanced chemical equation of the reaction. B. What is the pressure of the trapped air in torr? C. Calculate the pressure exerted by H 2 gas in torr given the vapor pressure of water at 22°C is 19.8 mmHg. 1 For number 14, assume Case A. 2 Citric acid is a triprotic acid
Prepared by: UPD College of Science Freshie Shiftee Transferee Circle ‘18-’19 First Semester D. How much moles of H 2 gas was produced in the experiment if the measured trapped air is 38.2 mL? E. Calculate the new volume (in mL) of H 2 gas if conditions are changed to STP. 15. Given the equilibrium system: Heat + CH 4 (g) + 2H 2 S (g) CS 2 (g) + 4H 2 (g) Indicate the direction in which the equilibrium will favor if A. More CH 4 (g) is added B. More H 2 S (g) is added C. Some CS 2 (g) is removed D. The temperature is raised

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• Spring '19
• Avena
• Thermodynamics, UPD College of Science Freshie Shiftee Transferee Circle

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