In this organic chemistry lab, why do we determine melting points?
It helps to determine the purity or identity of a sample.
What is the "eutectic point"?
The lowest melting point of a mixture of two diferent compounds.
Fill in the blank. The melting point of a compound is a property.
physical
Why does an impurity broaden a "melting range"?
The impurity disrupts the molecular interactions in diferent areas of the sample
Why shouldn't you reuse a sample that was previously melted, even though it has solidified again?
Some of the sample may have decomposed at or near the melting point.
. Why should you pack the substance well in the melting point capillary tube?
Because there will be air pockets in the capillary causing to obtain a lower melting range than the actual range.
What two errors in the data will result if you raise the temperature of the melting point
apparatus too quickly?
1)Not able to detect the proper melting range
2)Compound may melt at once and may not be able to get the melting point at all
Suppose you make a 50/50 mixture of the compounds listed in the table below. You then
perform a mixed melting point determination. What temperature range would you expect
to see the sample melt? Choose the best answer below:
The melting range of the mixture should be lower and broader
What would an air pocket in the sample do to the melting point?
Increase the melting point temperature
One of my graduate students was measuring out samples of vanillin and acetamide and
placed them on a watch glass for analysis. She did not label the samples and they both
look very similar. How could she determine which sample was which? Briefly describe
She can take the melting point of each compound and compare it with the melting points range to find out the melting poiint of each to identify each compound.