Boiling Point Definition: The temperature at which the vapor pressure of the liquid is equal to atmospheric pressure. The boiling point of a liquid varies according to the applied pressure and hence increases with increased pressure. At sea level, water boils at 100° C (212° F), while at higher altitudes the temperature of the boiling point is lower.
Intermolecular forces and boiling point
The stronger the intermolecular forces, the higher the boiling point and the lower the vapor pressure of the substance and the higher the boiling point and the weaker the intermolecular force, lower the boiling point and higher the vapor pressure.
Is boiling point a physical or chemical property?
Physical property accounts for the change in the state: solid to liquid; solid to gas; liquid to gas without any change in their chemical composition. When water boils at 100o Celsius, a change in state from liquid to vapor takes place with neither change in chemical bonds nor the formation of new substances. Hence, the boiling point is considered a physical property.
Boiling points of some materials/chemicals:
| Compound | Boiling point | Compound | Boiling point |
| Water | 100oC | HCl | – 82.05oC / 188.1K |
| Methanol | 64.7oC | HBr | – 66oC / 207.1K |
| Ethanol | 78.37oC | HF | 19.5oC |
| Acetone | 56oC | NH3 | – 33.34oC / 239.8K |
| Toluene | 100.6oC | SiH4 | – 112oC / 161.1K |
| Alcohol | 78.37oC | Milk | 100.5oC |
| Benzene | 80.1oC | CO2 | – 78.46oC / 194.7K |
| Cyclohexane | 80.75oC | NaCl | 1465oC |
| Diethyl ether | 34.6oC | NaHCO3 | 851oC |
| Ethylene glycol | 197oC | Dichloromethane | 39.6oC |
| Isopropyl alcohol | 82.5oC | Iodine | 184.3oC |
| Benzoic acid | 249.2oC | Helium | – 268.9oC / 4.22K |
| Sulphuric acid | 337oC | Argon | – 185.8oC / 87.3K |
| Acetic acid | 118oC | Oil | 300oC |
| Methane | – 161.6oC / 111.5K | Oxygen | – 183oC / 90.19K |
| Ethane | – 89oC / 184.1K | Hydrogen | – 252.9oC / 20.28K |
| Propane | – 42oC / 231.1K | Nitrogen | – 195.8oC / 77.36K |
| Butane | – 1oC / 272.2K | Fluorine | – 188.1oC / 85.04K |
| Pentane | 36.2oC | Chlorine | – 34.04oC / 239.1K |
| Hexane | 69oC | Br2 | 58.8oC |
| Heptane | 98.42oC | CCl4 | 76.72oC |
| Octane | 125.6oC | H2S | – 60oC / 213K |
| Ethyl acetate | 77.1oC | CH3OCH3 | 24oC / 249K |
| Diethyl ether | 34.6oC | CO | – 191.5oC / 81.65K |
| 1-butanol | 117.7oC | NaOH | 1388oC |
| 1-propanol | 97oC | Cyclohexane | 80.75oC |
FAQ:
What is boiling point?
Boiling point is the temperature at which the vapor pressure of the liquid is equal to atmospheric pressure.
What is the boiling point of water (in celsius)?
The boiling point of water is 100 degree celsius.
What is the boiling point of water in Fahrenheit?
The boiling point of water is 212o F
Is boiling point a physical property?
Yes, boiling point is a physical property because when a liquid boils, change in the state takes place without changing its chemical composition.
What is the boiling point of ethanol?
The boiling point of ethanol is 78.37oC .
Boiling point equation
The boiling point equation is: Δ T = mKb, where m is molality, and Kb is molal boiling point-elevation constant.
Boiling point elevation formula
The boiling point elevation formula is: Δ T = mKb, where m is molality, and Kb is molal boiling point-elevation constant.
How is vapor pressure related to boiling point?
Boiling point is the temperature at which the vapor pressure of the liquid becomes equal to atmospheric pressure. In general, the boiling point decreases with an increase in vapor pressure.
