145 148 151 153 ulbxypropiophenone Adipic Acid Citric Acid Questions 1) Ex plain

Question

145 148 151 153 ulbxypropiophenone Adipic Acid Citric Acid Questions 1) Ex plain what is meant by a colligative property? Other than freezing (melting) point depression and boiling point elevation, name one other colligative property. 2) All compound actually melt over a range of temperatures, rather than at a single temperature, therefore reporting a melting range is simply stating what is actually observed. Other than this, why should a melting range rather than a melting point always be reported? An unknown compound, X, has the melting point 112.5 114°C. It is suspected that X is either A or B, each compound having reported mp's of 1 15°C. Assuming Xis A, ndicate the mp range (give actual values) for the mixed mp's of a) X and A and b) X and B. 3) 4) An unknown compound, Y, has the meling point 124-125°C. It is suspected that Y is ether C It is suspected that Y is either C (reported mp 123°C) or D (reported mp 126°C), which compound, C or D is most likely to be Y? Why? Although the mixed melting point is a very simple and reliable procedure, it has one significant disadvantage in identifying an unknown compound. What is that disadvantage? 5) Doing the confirming experiments at the same time eliminates errors from using different heating rates for different determinations (and if different apparatuses were used for different determinations the errors in using different thermometers). 10

Explanation / Answer

1) The colligative properties of the solutions are those that, based on the properties of a solvent, are affected by the concentration of a solute in said solvent.

An example, Osmotic Pressure.

2) A solid is almost never pure in its entirety, it contains impurities that affect the point at which it changes from phase to liquid state, it is required, that a range of temperature is reported, instead of a single temperature, to cover the most situations.

3) For both cases a and b, the melting point remains constant (112.5ºC - 114ºC) because the two possible components have the same melting point and would not be affected.

4) Component D is the most similar to component Y, because the upper limit of the melting point range of Y is closer to the melting point of D.

5) This disadvantage lies in the confusion and misconception that could exist when comparing a range of melting point with a tabulated value.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.