Colligative properties are properties of a solution that depend on the amount of solute dissolved, and not dependent on the identity of the solute. The colligative properties studied in this current chapter of chemistry are: vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure.
The van’t Hoff factor for a solute is equivalent to the number of particles, in moles, will break apart in the solvent. When an …show more content…
The unknown solute is white, flaky and flat. It has rigid sides.
The dissolution of the solute in the para-dichlorobenzene occurs fairly quickly. When the solute was added it started melting immediately. The flakes started getting smaller, and with the aid of agitation the solute melted completely.
After dissolution was complete, the solution is clear, and resembles water. It also emits an upsetting odor.
As the solution solidifies, it appears around the inside of the test tube, it’s opaque, and it looks like ice.
The resulting molar weight for this lab was 103 grams. This molar weight was significantly lower than the molar weights of benzophenone and naphthalene. Naphthalene had the closest molar weight of 128.17 grams. The percent error was high at 19.6%. The reason the molar weight was too low because the final freezing point of the solution was too small. The change in temperature was increased, because of the greater difference between the final and initial temperature. To find the molality of the solution, the ∆T is divided by the molal freezing point constant of the solvent. When the ∆T is too great, the molality becomes too high. The molality multiplied by the kilograms of solvent used, results in the moles of solute being too high. The grams of solute divided by the moles of solute yielded in a molar weight too