# PS7 - room temperature How much water can he add before he...

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ChemE 3130 – Chemical Engineering Thermodynamics – Problem Set #7 (1) MDK 6.4 (2) MDK 6.5 (3) Sublimation: The vapor pressure of ice is 0.0885 psia @ T=32 o F and 0.096 psia @ T=30 o F. Determine the heat of sublimation of ice. (4) Partial molar properties: The enthalpy of a binary liquid mixture of species 1 and 2 at fixed T and P is given by: H ( x ) = 400 ξ 1 + 600 2 + 1 2 (30 1 + 42 2 29 Determine expressions for partial molar enthalpy of 1 and 2 H 1 , H 2 ( 29 as a function of x 1., numerical values for the pure species enthalpies (H 1 and H 2 ) and the partial enthalpy at infinite dilution H 1 , Η 2 ( 29 (5) 1 st law of acid chemistry: Do as you oughta’ , add acid to water   [insert Boston accent here]   A student needs to prepare 200g of an acid solution with 50wt% H 2 SO 4 . He neglects the first rule of acid chemistry and dilutes 100 g of concentrated acid (95 wt%, at 70 o F) with water. Assuming the mixing is adiabatic and all solutions are initially at
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Unformatted text preview: room temperature. How much water can he add before he gets into trouble. (trouble = If the solution reaches the boiling point of water (212 o F) additional water added to the system will boil and splash sulfuric acid ) [use the H-x diagram handed out in Lecture 22] His lab mate uses a different approach. She plans to mix both solutions (100g water and 100g conc. H 2 SO 4 ) by adding the acid to the water while cooling the solution in a surrounding ice bath. How much ice does she need to return the acid solution to room temperature after mixing? (assume that the cooling is only due to latent heat changes in the ice (i.e. melting)) The properties the cooling water / ice are: ∆ H fusion = 333 J/g ∆ H vaporization = 2260 J/g 1BTU = 1055 J 1 lbm = 453.4 g...
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## This note was uploaded on 11/10/2009 for the course CHEM 313 at Cornell.

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