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Is a sharp melting point for a crystalline organic substance always indicates a pure single compound?
Wiki User
∙ 11y ago
M. Bilal :)
Wiki User
∙ 11y ago
Wiki User
∙ 9y agoY,es the melting point of pure substances is always sharp. When unadulterated by impurities, the boiling point will always remain the same, or sharp.
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What is the identity of a substance?
The identity of a substance (chemical compound) is defined by his chemical formula and molecular structure.
Why is it necessary to use a powder rather than a crystalline sample when determining melting point?
with a crystalline solids ,transfer of heat will not be uniform which can cause an error in the determination of the melting point of a substance .
Who has higher melting point Pure or Impure Substance?
The melting point of an impure compound is almost *always* lower than that of a pure compound.
How does the arrangement of atoms in a crystalline substance differ from that in non-crystalline substance?
Crystalline solids exhibit cleavage: that is, when you break them, the nature of the break indicates the crystal structure. Thus, grinding a crystal of NaCl (which is cubic) inevitably produces small cubes of NaCl. Noncrystalline solids such as glass break into randomly-shaped pieces. Noncrystalline solids such as glass soften as the temperature increases and have no sharply defined melting point. On the other hand, quartz, which has the same chemical composition as glass but is crystalline, melts sharply at around 1650 degrees Celsius.
What are the criteria of purity of organic compound?
The property of an compound which is most frequently determined as a criteria of purity is the melting point because in general it may be said that a pure compound has usually a sharp melting point (i.e., the substance melts entirely within a rang of about 1 c) ,whereas an impure substance has an indefinite melting point, and will therefore melt slowly and indecisively over a rang of several degrees.
What does a melting point of a substance indicate?
It indicates that the substance has turned to a liquid.
What property of a substance indicates whether the substance is a liquid or a solid?
the melting point
A transparent crystalline substance is found to be rather soft and have a low melting point what type of solid is this substance?
ICE
What is a crystalline solids melting point?
Name this crystalline solid; each compound and material have a different melting point.
What is the identity of a substance?
The identity of a substance (chemical compound) is defined by his chemical formula and molecular structure.
What is the purpose of determining boiling point and melting point?
Boiling point- the temperature and pressure at which a liquid and a gas are in equilibrium. But also, it is very useful in determining the purity of a substance. If the melting point is known of the pure substance, than you can measure the melting point of what you've got and see if it matches. If the melting (or boiling) point is the same, than that is a good indication that the compound you have is what you think it is, and it is pure. If they are different from each other, that indicates that your compound is not pure.
Why urea has sharp melting point but glass does not?
Urea is a pure crystalline compound so has a sharp melting point while glass is an amorphous mixture.
How you know specific compound from another by melting point?
Melting point is a unique characteristic of a substance.
How is the melting of an impure compound expected to change with recrystallization?
The melting point of an impure compound will become closer to that of the actual melting point of the pure substance with recrystallization of your mixture.
Why is it necessary to use a powder rather than a crystalline sample when determining melting point?
with a crystalline solids ,transfer of heat will not be uniform which can cause an error in the determination of the melting point of a substance .
How do you know a compound is ionic or molecular?
An ionic compound is a pure substance that is formed from a metal and a nonmetal. It has a fairly high melting point and is a conductor of electricity when in a molten or aqueous state . A molecular compound, on the other hand, is a pure substance that is formed from nonmetals. It has a fairly low melting point, and cannot conduct electricity regardless of state. Another important difference between the two is that an ionic compound is a crystalline solid at standard ambient temperature and pressure (SATP), whereas a molecular compound can be in a solid, gas or liquid state at SATP.
What is purity criteria?
The criteria of purity of a compund isÊdetermined at it melting point.ÊA pure compound a definate melting point. While an impure substance has an indefinate melting point.
