Impure substances have different melting/ freezing points than their pure counterparts because the substance that was dissolved into the pure substance had a different melting point (higher or lower depending on the substance). When the freezing points of the two substances average out, a new freezing point is created. The freezing point/ melting is not necessarily lower
The boiling and melting points of pure substances vary based on the substance. Gasses for example have lower boiling and melting points than metals.
This greatly depends on the impurity but most common is a lower melting point for impurified substances: Ice with salt or sugar.
The melting point of an impure compound is almost *always* lower than that of a pure compound.
Remember that the more impure the lower the melting point.
Melting and freezing are synonyms; impure water freeze at a lower temperature than pure water.
Different substances have different typical melting points, so by observing the melting point of something you can narrow down the options for what it is. Usually, metals have higher melting points and non-metals have lower melting points.
Nope; not always. So the answer would be false. You have to realize that there might be impure substances mixed. Likewise impure substance can either lower the melting point or increase it :)M. Bilal :)
Covalent compounds have lower melting points.
The presence of the impurities will cause the boiling points to rise (also the melting points to fall). When you add the impurities, the substance doesn't remain pure affecting the boiling point to increase because now, more energy is required to boil the liquid with impurities. The melting points fall because impure substances require less energy to separate the particles.
the impurities will lower the melting point value.
the melting point of IMPURE water is lower because excess chemicals and sediments (and whatever else making it impure) get in the way of the water freezing directly by making it so that when the the water froze, it also had to freeze the sediments and chemicals (or else it wouldn't be frozen)
An impure sample will have a lower melting point, and will also have wider melting point range than that of a pure sample of the same substance. a sharp melting point range can also indicate a eutectic mixture
For example covalent compounds have a lower melting point.
Covalent compounds have a lower melting point.
The boiling and melting points are almost unique to individual substances. If it should happen that two possible substances have the same melting point, they can still be identified by the method of mixed melting points. If substances A and B have the same melting point and you mix them, the mixture will melt belowthe tabulated temperature. Thus if you mix your unknown with a sample of what you think it is, if you are right it will still melt sharply at the expected temperature, but if you are wrong it will melt gradually and at a lower temperature.
Monatomic substances have a low melting point an boiling point because they are held together by van der Walls forces which are very weak electrostatic attractions so less energy is needed to break them apart resulting in a lower boiling and melting point.
Compared to ionic compounds, Molecular compounds generally have lower melting points and boiling points.
Molecules with a covalent bond have lower melting points.
impurities lower the magnitude of melting point of as substance. And it increases the magnitude of boiling point.
These are organic compounds.
Because have lower melting points and boiling points
They get lower as the atomic number increases
For example covalent compounds.
Molecular compounds tend to have lower melting points.
because it helps to decrease the freezing point and if water is impure than its impurities lower the melting point.