Difference between revisions of "Boiling Point"
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*[[Boiling Point|Boiling point]] is defined as the [[temperature]] at which the [[Vapour Pressure|vapour pressure]] of the [[liquid]] equals the [[Atmospheric Pressure|atmospheric pressure]]. | *[[Boiling Point|Boiling point]] is defined as the [[temperature]] at which the [[Vapour Pressure|vapour pressure]] of the [[liquid]] equals the [[Atmospheric Pressure|atmospheric pressure]]. | ||
*[[Boiling Point|Boiling points]] vary with altitude due to changes in [[Atmospheric Pressure|atmospheric pressure]]. | *[[Boiling Point|Boiling points]] vary with altitude due to changes in [[Atmospheric Pressure|atmospheric pressure]]. | ||
| − | *The [[Boiling Point|boiling point]] is a characteristic property of a substance. | + | *The [[Boiling Point|boiling point]] is a characteristic property of a substance and therefore can be used to characterise and identify substances. |
*[[Boiling Point|Boiling point]] can be used to identify and purify [[liquid]]s as impurities in a [[liquid]] can raise or lower its [[Boiling Point|boiling point]]. | *[[Boiling Point|Boiling point]] can be used to identify and purify [[liquid]]s as impurities in a [[liquid]] can raise or lower its [[Boiling Point|boiling point]]. | ||
| + | *The [[Boiling Point|boiling point]] is a key concept in [[thermodynamic]]s and [[State Change|phase transitions]]. | ||
===Examples=== | ===Examples=== | ||
Revision as of 13:13, 22 May 2024
Contents
Key Stage 4
Meaning
Boiling point is the temperature at which the particles in a liquid gain enough energy to form a gas.
About Boiling Points
- Different substances have different boiling points.
- The boiling point of a substance is determined by the strength of the bonds which hold the particles close together in a liquid. The stronger the bonds the higher the boiling point.
- When a substance is heated to its boiling point it will remain at this constant temperature until all of the liquid has boiled.
- The boiling point of pure water is 100°C or 373 Kelvin.
- Adding salt to water can increase its boiling point, causing it to boil at a higher temperature. This is because the salt increases the force of attraction between adjacent particles.
- The Noble Gases all have very low boiling points because there is a very weak force between the atoms.
References
AQA
- Boiling points, pages 155-6, GCSE Combined Science Trilogy 2, Hodder, AQA
- Boiling points, pages 36-37, 47, GCSE Chemistry; Third Edition, Oxford University Press, AQA
- Boiling points, pages 80-81, 85, GCSE Physics; Third Edition, Oxford University Press, AQA
- Boiling points; alkali metals, page 26, GCSE Chemistry; Third Edition, Oxford University Press, AQA
- Boiling points; halogens, page 28, GCSE Chemistry; Third Edition, Oxford University Press, AQA
- Boiling points; hydrocarbons, pages 150-151, GCSE Chemistry; Third Edition, Oxford University Press, AQA
- Boiling points; purity analysis, pages 180-181, GCSE Chemistry; Third Edition, Oxford University Press, AQA
Edexcel
- Boiling point, page 147, GCSE Combined Science, Pearson Edexcel
- Boiling point, page 3, GCSE Chemistry, Pearson, Edexcel
- Boiling point; ionic compounds, page 182, GCSE Combined Science, Pearson Edexcel
- Boiling point; ionic compounds, page 38, GCSE Chemistry, Pearson, Edexcel
- Boiling point; molecular compounds, page 186, GCSE Combined Science, Pearson Edexcel
- Boiling point; molecular compounds, page 42, GCSE Chemistry, Pearson, Edexcel
- Boiling, page 98, GCSE Chemistry, CGP, Edexcel
OCR
- Boiling points, pages 76-77, Gateway GCSE Chemistry, Oxford, OCR
- Boiling points; distillation, pages 44-45, 238-239, 270-271, Gateway GCSE Chemistry, Oxford, OCR
- Boiling points; hydrocarbons, pages 238-239, 241, Gateway GCSE Chemistry, Oxford, OCR
- Boiling points; measuring, pages 10-11, 270-271, Gateway GCSE Chemistry, Oxford, OCR
- Boiling points; metals versus non-metals, page 52, Gateway GCSE Chemistry, Oxford, OCR
- Boiling points; trends in Periodic Table, pages 134, 139, Gateway GCSE Chemistry, Oxford, OCR
Key Stage 5
Meaning
The boiling point is the temperature at which a pure liquid at atmospheric pressure boils.
About Boiling Point
- Boiling point is defined as the temperature at which the vapour pressure of the liquid equals the atmospheric pressure.
- Boiling points vary with altitude due to changes in atmospheric pressure.
- The boiling point is a characteristic property of a substance and therefore can be used to characterise and identify substances.
- Boiling point can be used to identify and purify liquids as impurities in a liquid can raise or lower its boiling point.
- The boiling point is a key concept in thermodynamics and phase transitions.
Examples
- The boiling point of water at sea level is 100°C.
- Ethanol boils at around 78°C at standard atmospheric pressure.