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Name: Matthew Heine
Status: student
Age: 15
Location: N/A
Country: N/A
Date: Around 1999


Question:
Is sucrose a covalent or ionic bond?

Is melting point a characteristic property of the different bonds (ionic & covalent)? If so, which has lower melting points?


Replies:
Dear Matthew,

The short answer is yes. The stronger the bonds between molecules, the higher the melting point will be. Since ionic bonds are the strongest of all, ionic solids (like salt) tend to have higher melting points than other solids (like sugar).

Best Regards,

Prof. Topper
Dept of Chemistry
The Cooper Union new york, ny


Hi Matthew,

Typically, a covalently bound molecule will have a lower melting point than an ionically bound molecule. This is because a covalently bound molecule has bonds that tie specific atoms together to form a single molecular unit, whether it is a solid, liquid, or gas. Thus, bonding between different molecules of the substance only occur by forces such as the Van der Waals forces which are relatively weak, resulting in a low melting point. Ionic bonds are the result of opposite charges attracting and are non-directional. As a result, a cation is bound equally to all its nearest neighbor anions (and vice versa). This is a stronger bond than the Van der Waals forces and the melting points are higher.

Greg Bradburn



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