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Yes, at different pressures, the same substance will melt at two different temperatures. In fact, graphs that highlight this trend are called phase diagrams.
Wiki User
∙ 13y ago
A substance can have more than one melting point if it undergoes polymorphism or exhibits different crystal structures at different temperatures. Different crystal structures can have different melting points due to variations in the arrangement of atoms or molecules. Therefore, the substance can melt at different temperatures depending on the crystal structure present.
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What is the simple physical test to show that a sample of water is pure?
A scientific test you do on water similar to a chemical test
Why does the temperature become constant at the point of melting till the whole substance of a solid melted?
That happens because any heat that is added to that melting material will be used to cause further melting, until there is nothing left to melt, at which point the added heat can raise the temperature. A solid melts at its melting point; it does not get hotter than the melting point without melting, that's why it is the melting point.
What happens if boiling point is higher than melting point?
The boiling point is always higher than the melting point.
What can change diamond to liquid or gas?
Extreme heat, more than 3500 °C, the highest melting point of any substance (3820 degrees Kelvin = 3547 degrees C).
Is the melting point of bromine higher or lower than the melting point of chlorine?
The melting point of bromine is -7,2 0C. The melting point of chlorine is -101,5 0C.
Higher melting point than expected?
It is indeed possible for a substance to have a higher melting point than expected. This normally happens when the substance is impure.
When an obtained melting point range is broad what does it tell about the substance?
strong intermolecular forces attract the molecules
When the observed melting point is less than the stanadr value what inference will you get?
The substance whose melting point is being observed is impure.
Which is true of a melting point and a boiling point?
Melting point: at this temperature a solid become a liquid.Boiling point: at this temperature a liquid become a gas.
What is the simple physical test to show that a sample of water is pure?
A scientific test you do on water similar to a chemical test
Is the boiling point of something the same as the melting point?
The boiling point is the temperature at which the vapor pressure of the liquid is equal to the external pressure. It is also the condensation point. The freezing point is the temperature at which liquid and solid coexist in equilibrium. It is also the melting point.
The temperature at which a substance freezes is lower than the temperature at which it melts?
Correct, the temperature at which a substance freezes is lower than the melting point.
How would you determine the melting of a substance whose melting point is higher than 100c?
Use a thermometer that can measure greater than 100 oC.
Is it true that it takes a lot of heat to melt a substance with a low melting point?
See the expert answer above for a specific answer to the question. However, if you mean 'what is a low melting point' then it means that the temperature at which the substance becomes a liquid is reasonably easy to get to, so you have to provide less heat to get to the melting point than you would if it were high.
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 does the temperature become constant at the point of melting till the whole substance of a solid melted?
That happens because any heat that is added to that melting material will be used to cause further melting, until there is nothing left to melt, at which point the added heat can raise the temperature. A solid melts at its melting point; it does not get hotter than the melting point without melting, that's why it is the melting point.
Why is melting point of ammonia lower than water?
The melting point of a substance is based upon the polarity of the bonds that make up the substance. In water, the O-H bond has a difference in electronegativity of 1.4 (Pauling's Scale) and in ammonia, the N-H bond has a difference in electronegativity of .9. Therefore, it takes more energy to break apart the O-H bond because the polarity is so great, and this is why it has a higher melting point than ammonia.
