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Yes, pure substances have fixed boiling points under specific pressure conditions. This is because a pure substance has a uniform composition, allowing it to transition from liquid to gas at a consistent temperature. However, the boiling point can vary with changes in atmospheric pressure; for example, water boils at 100°C at sea level but at lower temperatures at higher altitudes. Impurities in a substance can also alter its boiling point, leading to boiling point elevation or depression.
What else can I help you with?
Is boiling point and melting point able to change for a pure substance?
Neither are actually points as such, but lines on a scale comparing temperature and pressure. Increase one and the size of the other goes up as well before the material will change state. So in effect, yes, the points do change, depending on the environment they are in at the time.
Does a pure substance boils at -100c?
A pure substance can boil at -100°C if its boiling point is indeed at that temperature under standard atmospheric pressure. For example, substances like liquid nitrogen boil at -196°C, while others, like certain hydrocarbons, may have boiling points that are higher. The boiling point of a pure substance is determined by its molecular structure and intermolecular forces. Therefore, whether a pure substance boils at -100°C depends on its specific properties.
What is one characteristic of a sample of matter that indicates it is a pure substance?
A pure substance is a material which contains atoms of only one kind. It has fixed physical and chemical properties like boiling point, melting point, valency, density.
Do pure substances have a fixed boiling and melting point?
yes they have
How could you use the physical properties of melting and boiling point to identify a substance?
If you know the melting point and boiling point of a substance, you could look them up in a table to see what substances have those melting and boiling points. In practice, there are lots of other tests you'd probably want to do in addition, because in general there's no guarantee that an unknown substance is a single pure compound.
How do the boiling point ranges show that each fraction is a mixture of different compounds instead of a pure substance in fractional distillation?
In fractional distillation, each fraction has a range of boiling points because it contains a mixture of compounds with varying boiling points. As the temperature increases during distillation, the compounds with lower boiling points vaporize first, followed by those with higher boiling points. The overlapping boiling point ranges in each fraction indicate the presence of multiple compounds rather than a single pure substance.
How can you tell a pure substance from a mature by its boiling point?
take water for example, if water boils at 100 degrees Celsius then it is pure. if the boiling temperature turns out to be higher or lower (most of the time it is higher) then a substance is impure. salt water boils at 102.8 degrees Celsius.
Describe what a pure material or substance is?
These are substances that contain only one type of atoms/molecules. For example, diamond is a pure substance. Diamonds are made of strictly carbon atoms. Melting points and Boiling points of pure substances always remain constant !
How can the melting and boiling point help you identify it?
Melting and boiling points are physical properties unique to each substance, so knowing these values can help identify a substance. By comparing the observed melting and boiling points of an unknown substance to known values in a database, you can narrow down the possible identities of the substance. Substances with similar melting and boiling points are more likely to be the same compound.
Is boiling point and melting point able to change for a pure substance?
Neither are actually points as such, but lines on a scale comparing temperature and pressure. Increase one and the size of the other goes up as well before the material will change state. So in effect, yes, the points do change, depending on the environment they are in at the time.
What determines the upper and lower fixed points of a thermometer?
Upper fixed point is the temperature of pure water boiling at normal atmospheric pressure.Lower fixed point is the temperature of a mixture of pure ice and pure water at normal atmospheric pressure. Each thermometer has a scale containing an upper and lower fixed points depending on the use of this thermometer for specific measurements.
Does a pure substance boils at -100c?
A pure substance can boil at -100°C if its boiling point is indeed at that temperature under standard atmospheric pressure. For example, substances like liquid nitrogen boil at -196°C, while others, like certain hydrocarbons, may have boiling points that are higher. The boiling point of a pure substance is determined by its molecular structure and intermolecular forces. Therefore, whether a pure substance boils at -100°C depends on its specific properties.
What are fixed compositions?
pure substance
What is one characteristic of a sample of matter that indicates it is a pure substance?
A pure substance is a material which contains atoms of only one kind. It has fixed physical and chemical properties like boiling point, melting point, valency, density.
How can boiling point be used to find out if a substance is pure?
At Boiling Point all the material evaporates leaving no residue which means it is pure. But if it leaves some residue after evaporating at boiling point then it is not pure. For example : If you take an example of pure water & Saline Water then pure water will evaporate at its boiling point leaving nothing after it. But Saline water evaporates leaves salt behind it.
What substance has the simplest pure substance with a fixed composition?
You think probable to a pure stoichiometric compound.
How could the identify of a compound be established by melting point?
Pure substances have very specific melting (and boiling) points. Assuming the substance is pure you could measure the melting point and compare it to a known database of melting points.
