Exp184

=Researcher= Sozit Kurtu =Objective= To qualify near-melting point behavior with regards to solubility, specifically in the case of [|cyclohexanecarboxylic acid] in hexanes. =Procedure= =Results= [|Calculations] =Discussion= Hexanes were used rather than pure n-hexane. For accuracy, the experiment should be repeated with n-hexane. Also, due to the melting point of 35-37C, cyclohexanecarboxylic acid exists in a glass-like state at room temperature, which may effect weight measurements. I do not believe that either of these will prove to dispute the following conclusions. =Conclusion= Cyclohexanecarboxylic acid appears to be highly soluble (at least 5M) or totally miscible in hexanes at room temperature and down to -8.5C. Added to [|SolSum] as miscible based on density/MW (8.06M) =Log=
 * 1) Make 0.25M, 0.5M, 0.75M, 1.0M, 1.25M, 2.5M, and 5.0M solutions of cyclohexanecarboxylic acid in hexanes at room temperatue.
 * 2) Set water bath to room temperature to equilibrate.
 * 3) Insert tubes in a way that facilitates periodic removal to examine samples. Make sure that all samples are completely submerged in the bath.
 * 4) Decrease temperature in increments of 5C, checking each sample after equilibration for precipitation.
 * 5) Sonicate periodically to prevent supersaturation.
 * 6) Continue until sample precipitates, or until the lower limit of water bath.

2010-10-08
11:30 - Made 0.5M sol'n of cyclohexanecarboxylic acid in hexanes.** (Tube B) 11:42 - Went into sol'n easily. 11:43 - Cleaned flask. 11:45 - Made 0.75M. (Tube C) 11:57 - Required shaking to go into sol'n. 12:00 - Made 0.25M. (Tube A) 12:07 - Made 1M. (Tube D) 12:14 - Went into sol'n, took slightly longer (not quantified). 12:18 - Made 1.25M. (Tube E) 12:27 - Went into sol'n. 12:31 - Set bath to 40C. Actual = 19C. Added samples in 20mL screw-top tubes. 13:18 - Made 2.5M (Tube F). Made 5M (Tube G). 13:34 - Set to 25C. Actual = 40C. 13:45 - Set to 20C. Actual = 25C. 13:53 - Set to 15C. Actual = 20.5C. 14:00 - Sonicated for 20s. Still dissolved. 14:01 - Set to 10C. Actual = 14C. 14:08 - Set to 5C. Actual = 11C. 14:14 - Sonicated for 25s. Still dissolved. 14:16 - Set to 0C. Actual = 4C. 14:23 - Set to -5C. Actual = 1C. Sample G cloudy. 14:32 - Sonicated for 20s. Cloudy sample did not precipitate; heat from sonication caused immediate redissolution. 14:33 - Set to -10C. Actual = -4C. One sample 14:49 - Set to -15C. Actual = ? (misread). 15:05 - Ice formed. -8.5C.