Why impurities decrease melting points.

Thread starter yaseen shah
Start date Mar 24, 2010
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decrease Impurities Melting Points

In summary, impurities decrease melting points by disrupting the regular pattern of molecules or atoms in a substance, making it more difficult for the substance to overcome intermolecular forces and resulting in a lower melting point. They do this by creating defects in the crystal lattice, which make it easier for the substance to break apart and melt at a lower temperature. Any type of impurity, including foreign substances and structural defects, can decrease melting points with no specific limit to the amount of decrease. The effect of impurities on melting points varies for different substances, with some experiencing an increase, no change, or a decrease in melting point depending on the properties and interactions between the impurity and the substance.

Mar 24, 2010

yaseen shah

anyone tell me why melting points of any substance decrease when we add any other material

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Mar 24, 2010

Mapes

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They don't always; consider http://www.spaceflight.esa.int/impress/text/education/Images/Solidification/PhaseDiagrams/Phase_Diagrams_Image_001.png" , for example. Do you have a particular system in mind?

Last edited by a moderator: May 4, 2017

1. Why do impurities decrease melting points?

Impurities decrease melting points because they interrupt the regular pattern of molecules or atoms in a substance. This makes it more difficult for the substance to overcome the intermolecular forces holding it together, resulting in a lower melting point.

2. How do impurities disrupt the melting process?

Impurities disrupt the melting process by creating defects in the crystal lattice of the substance. These defects make it easier for the substance to break apart and melt at a lower temperature.

3. Can any type of impurity decrease melting points?

Yes, any type of impurity can decrease melting points. This includes foreign substances, as well as structural defects within the substance itself.

4. Is there a limit to how much impurity can decrease a melting point?

There is no specific limit to how much impurity can decrease a melting point. The amount of decrease depends on the type and amount of impurity present, as well as the properties of the substance itself.

5. How do impurities affect the melting points of different substances?

Impurities affect the melting points of different substances in different ways. In some cases, impurities may increase the melting point, while in others they may have no effect or decrease the melting point. It depends on the specific properties and interactions between the impurity and the substance.