Different substances usually have different melting points, so determining the melting point of a substance can narrow down the possibilities for the identity of the substance. Likewise different substances usually differ in their boiling points, so boiling point can narrow down the possible identities of a substance. Although two substances can have nearly identical melting points or have nearly identical boiling points, it is extremely rare for two different pure substances to have BOTH the same melting point AND the same boiling point, so taking the two together is usually enough to uniquely identify a substance, or at the very least narrow it down to a very small list.
Also, surprisingly, if you mix two substances with the same melting point, the mixture will NOT melt at the expected temperature, so when you have a shortlist based on melting point you take your unknown and mix it with one of the suspects. If it melts at the right temperature, you have identified it. If not, you try the next one.
The boiling point of at mixture depends on the constituents. Sometimes it is higher than both constituents, sometimes it is lower than both constituents. This depends on the interactions between the molecules. Alloys always melts at a lower temperature than the pure metals, often over a temperature range. The temperature at which melting begins is called the solidus, and the temperature when melting is just complete is called the liquidus.
The melting point of a mixture will be lower and more broad than a pure substance. One of the main characteristics of a molecule's melting point is it's symmetry because this influences the molecule's ability to packed together well. The more packed together the molecule, the tighter the molecules are together, and therefore the higher the melting point. So if you add something into your pure mixture, the ability of it to pack together well is more difficult, which would decrease the melting point.
A pure substance generally has fixed melting and boiling points. Note it must melt or boil without decomposition. The measured values can be used as a guide to identification. Remembering that impurities depress the melting point and elevate the boiling point the "sharpness" of the melting/boiling point is an indication of purity.
There are three common "phases" of matter, solid, liquid or gas. They differ in how easily the the individual molecules that make up the matter can move. In solids, the molecules are bound into a specific location in the solid. The only way to move them is to break the solid. When enough heat is added, the molecules vibrate with enough energy that they break free from their local bonds and can move around short distances, although they remain weakly bonded to other molecules nearby. This is melting and the resulting phase is a liquid. If even more heat is added, the molecules eventually have enough energy to break free from the other molecules more completely and become a gas. This is called vaporization (i.e., boiling). A glass is a special case intermediate between solids and liquids. Finally, if even more heat is added, the molecules and atoms break apart into a gas made up of atomic fragments, which typically have a positive or negative charge. This phase is called a plasma. Some molecules (such as carbon dioxide--dry ice) can skip the liquid state and go directly from solid to gas when they are heated.
The melting point of a substance, at a specified pressure, is the temperature at which it changes phase - from solid to liquid. The boiling point is the temperature at which the phase changes from liquid to gas.
Melting point: change of phase from solid to liquid.
Boiling point: change of phase from liquid to gas.
They're both phase-transition temperatures. The melting point is the solid-liquid phase transition temperature. The boiling point is the liquid-gas phase transition temperature.
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The phase change when gas turns directly into a solid is called:
EUTECTIC point is the lowest possible melting point of a mixture of two substance .wereas TRIPLE point is the condition under which three phases of a substance coexist in eqilibrium.
"A chemical compound is a pure material made out of a combination of two or more chemical elements that have been bonded through chemical procedures." " a chemical mixture is considered to be impure substance. What make it different from a compound is that a compound or pure substance contains constant composition; furthermore, chemical mixtures can be both created and separated physically and simply do not require chemical processes." Andrew Daniel (Dec 28th, 2010). Difference Between Compound and Mixture [http://www.differencebetween.com/difference-between-compound-and-mixture/] Read more: http://www.differencebetween.com/difference-between-compound-and-mixture/#ixzz24s4xuMGx Read more: http://www.differencebetween.com/difference-between-compound-and-mixture/#ixzz24s4i8zWd
A mixture is when there is a substance made of mre than one type of element or compound. A solution is when you take two or more substances, which form a molecular bond.
The major difference between a solution and an ordinary mixture is that solution is homogeneous and an ordinary mixture is heterogeneous.
In a homogenous mixture the substance are so evenly distributed that it is difficult to distinguish one substance in the mixture from another but it only contains only one substance and it will appear the same. In a heterogenous mixture the parts of the mixture are noticeably different from one another and the mixture is different and kind.
The difference between a homogeneous mixture and a pure substance is that a pure substance has a fixed composition and cannot be separated because it is chemically bonded and a homogeneous mixture can be separated.
No.
EUTECTIC point is the lowest possible melting point of a mixture of two substance .wereas TRIPLE point is the condition under which three phases of a substance coexist in eqilibrium.
A substance is equivalent to one compound, with a definited chemical formula. A mixture is a...mix of two or more substances (compounds).
Frequently it is not possible.
A compound is a simple substance, a mixture is formed from two or more compounds.
In a heterogenous mixture you can see the different parts that make up the mixture. In a homogenous mixture one substance is dissolved in another and therefore only one substance is visible.
A mixture is when a substance consisting of two or more substances mixed together. A solution is is a substance with two or more substances that are completely dissolved in the other.
A mixture contain two or more compounds; these compounds can be separated with less or more difficulties.
The easiest way to check is if there is a difference in colours between parts of the mixtures.
A compound is a simple substance, a mixture is formed from two or more compounds.A mixture can be separated by physical procedures, a compound not.
A compound is a simple substance, a mixture is formed from two or more compounds.A mixture can be separated by physical procedures, a compound not.