0
What else can I help you with?
Why crystalline solids have sharp melting points whereas amorphous do not?
"As the atoms of Crystalline solids have specific shape and same distance,so they have same K.E,intermolecular forces of attraction and geometrical shape due to which Crystalline solids are blessed sharp melting points."
Why is cinnabar not a pure substance?
Cinnabar is not a pure substance because it is a mineral composed of mercury sulfide and may contain impurities or other elements mixed in its crystalline structure. This impurity affects the chemical composition of cinnabar, making it a mineral rather than a pure substance.
How do impurities affect the melting point of compound?
effects that impurities have on melting point iof a pre compound. I learned that it is because the impurities "defect" the crystal lattice of the compound. A pure compound is a structure of high molecular symmetry. An impurity is rather assymetrical, or is a poorly organized structure. If the impurites are present with the pure compound, the melting point will deviate because melting point is also dependent on the high symmetry and organization of molecular structures,
Under what conditions heat can be given to a substance without raising its temperature?
If the substance is in solid condition and at the melting temperature, heat can be given without rising the temperature. Then the substance melts and all the heat will be used in the melting process. Also when the substance is at the boiling temperature you can add heat without rising the temperature. At that point the heat is used to vaporate the substance.
Why temperature remains constant at melting and boiling point of substance?
The temperature remains constant at the melting and boiling points of a substance because all the energy added during these phase changes is used to break intermolecular bonds rather than increase the kinetic energy of the molecules. During melting, the energy breaks the bonds holding the solid structure together, while during boiling, it overcomes the forces keeping the liquid molecules together. As a result, temperature does not rise until the entire substance has completely transitioned to the next phase.
What kind of crystalline solids?
It is a network solid, a lattice of many covalent bonds (like diamond, except that it is black rather than transparent).
What kind of solid crystalline boron?
It is a network solid, a lattice of many covalent bonds (like diamond, except that it is black rather than transparent).
Is NaCl the substance with the lowest melting point is?
NaCl, common table salt, has a rather high melting point. The substance with the lowest melting point is helium. Helium has no solid phase, it melts at any temperature above absolute zero.
What is kind of solid is crystalline boron?
It is a network solid, a lattice of many covalent bonds (like diamond, except that it is black rather than transparent).
Why is it necessary to use a powder rather than a crystalline sample when determining melting point?
Using a powder sample allows for a more accurate measurement of the melting point because it provides a more uniform surface area for heating and minimizes the effect of any impurities. In contrast, a crystalline sample may have uneven surfaces that can lead to misleading results or unreliable melting point values.
Why crystalline solids have sharp melting points whereas amorphous do not?
"As the atoms of Crystalline solids have specific shape and same distance,so they have same K.E,intermolecular forces of attraction and geometrical shape due to which Crystalline solids are blessed sharp melting points."
Maria is examining a sample of a fine white crystalline substance. Which test will demonstrate that she is looking at a compound rather than an element?
Chemical analysis shows that the substance contains sodium and sulfur.
Waxy material that melts gradually starting at 52 Celsius and finishes at 65 is it a pure substance mixture?
The waxy material described is a pure substance. It exhibits a melting point range, suggesting a specific compound with a defined melting temperature range, rather than a mixture of multiple substances with varying melting points.
Why is cinnabar not a pure substance?
Cinnabar is not a pure substance because it is a mineral composed of mercury sulfide and may contain impurities or other elements mixed in its crystalline structure. This impurity affects the chemical composition of cinnabar, making it a mineral rather than a pure substance.
How do impurities affect the melting point of compound?
effects that impurities have on melting point iof a pre compound. I learned that it is because the impurities "defect" the crystal lattice of the compound. A pure compound is a structure of high molecular symmetry. An impurity is rather assymetrical, or is a poorly organized structure. If the impurites are present with the pure compound, the melting point will deviate because melting point is also dependent on the high symmetry and organization of molecular structures,
Why is a melting point often referred to as a range and not an exact number?
A melting point is often given as a range because impurities, uneven heating, and other factors can cause the substance to melt over a range of temperatures rather than at a single, precise temperature. The range indicates that the substance begins to melt at the lower end and is completely melted at the upper end of the range.
The temperature at which a substance becomes a liquid?
It is different for different substances. the generic name for the temperature at which a solid becomes a liquid is the melting point. For a pure chemical compound or an element this is usually a sharp temperature rather than a range.
