1)effects of impurities on the boiling point of an organic compound. 2) purposes why melting points are determined. 3)suppose i am taking a melting point and the compound disappears, what must i do?
Have you put any thought into these or do you expect us to do your homework?
Here are some VERY limited answers. Repost if you need clarification but tell us what you don't understand about the problem.
1.effect depends upon if the compounds are volatile or not. Look up Raoult's law.
2. to determine the purity.
3. recheck the process. If the same thing happens, the point at which it disappears is called the decomposition point.
What is the effect of an insoluble impurity, such as sodium sulfate, on the observed melting point of a compound?
As an AI bot, I'm here to help explain the concepts behind your questions and provide guidance on how to find answers. I am not here to do your homework for you. Here's some explanation to the concepts you've asked about:
1) Effects of impurities on the boiling point of an organic compound:
Impurities can have different effects on the boiling point of an organic compound depending on their nature. In general, impurities can cause the boiling point of a compound to increase, decrease, or remain unchanged. It depends on whether the impurities are volatile or non-volatile.
If the impurities are volatile, they will tend to evaporate along with the organic compound and lead to a decrease in the boiling point. This is because the presence of the impurities disrupts the intermolecular forces between the organic molecules, making it easier for them to escape into the vapor phase.
If the impurities are non-volatile, they will remain in the liquid phase even after the organic compound has evaporated. This causes an increase in the boiling point because the presence of non-volatile impurities creates stronger intermolecular forces, making it more difficult for the organic compound to escape into the vapor phase.
To understand the effects of impurities on boiling point more thoroughly, you can look into Raoult's law, which describes the relationship between the vapor pressure of a component in a mixture and its mole fraction in the liquid phase.
2) Purposes of determining melting points:
Determining the melting point of a compound serves multiple purposes, including:
a) Identification: Melting point values are unique to specific compounds and can be used as a means of identifying unknown substances. By comparing the experimental melting point of an unknown compound to known values, you can make a preliminary identification.
b) Purity assessment: Pure compounds have well-defined melting points, while impurities can lower, broaden, or even eliminate the melting point range. By comparing observed melting points to the literature values for a pure compound, you can assess the level of purity.
3) Compound disappears during melting point determination:
If a compound disappears during the melting point determination, it suggests that the compound is undergoing decomposition rather than melting. To handle this situation:
a) Recheck the process: Ensure that the heating rate is appropriate and that the temperature range being used is suitable for the compound. Make sure you are using a correct method for determining melting point, such as using a melting point apparatus.
b) Observe if decomposition occurs: If the compound consistently disappears without melting, record the temperature at which this occurs. This temperature is referred to as the decomposition point and can be useful for characterization purposes.
Remember, it's important to have a good understanding of the underlying principles and theories behind these concepts. If you need further clarification or guidance, feel free to ask.