Boiling Point Calculator

In chemistry, the boiling point is defined as the temperature in which the liquid vapour pressure equals the external pressure surrounding the liquid. At the point of this temperature, the liquid is converted into the vapour state.Generally, when the liquid boils at one atmospheric pressure, then the temperature is called the normal boiling point. Usually, the boiling point of the liquid is affected by the altitude and the pressure

The normal boiling point is the temperature at which the vapour pressure is equal to the standard sea-level atmospheric pressure (760 mm of mercury). At sea level water boils at 100° C (212° F). At higher altitudes the temperature of the boiling point is lower. This boiling point is dependent on the pressure and substance latent heat of vaporization. A liquid at a higher pressure has a higher boiling point than when that liquid is at lower atmospheric pressure.

The boiling point calculator uses the Clausius–Clapeyron relation to establish the boiling point of any substance at a given pressure and temperature. The formula for boiling point is given as ln(P₁/P₂) = ΔH/R * (1/T₂ - 1/T₁)

• Where, T₁ is the temperature at boiling point at stage 1(at pressure equal to P₁)
• P₁ is the pressure at stage 1
• T₂ is the temperature at boiling point at stage2(at pressure equal to P₂)
• P₂ is the pressure at stage 2
• R is the universal gas constant = 8.3145 J/mol*K
• ΔH is the enthalpy of vaporization or latent heat of vaporization.

Another Formula for Boiling Point Kb = RTb2M/ΔHv

• Where, R is that the universal gas constant 8.3145 J/mol*K
• Tb is that the boiling temperature of the pure solvent [in K]
• M is that the molar mass of the solvent
• ΔHv is the heat of vaporization per mole of the solvent.

Example 1: What is the new boiling point prepared by adding 96 g of sodium chloride to 383 mL of water? The boiling point constant for water is 0.52°C/m.

Solution:

Given that,

Mass of sodium chloride = 96g

Molecular weight of NaCl = 58.44

Volume of solution in liters = 383/1000 = 0.383 lit

Boiling point constant Kb = 0.52°C/m.

Now find molarity of Nacl = no.of moles / volume in lit

= ( mass/ mol.wt ) / volume in lit

= (96/58.44) / 0.383 = 4.2888m

Formula for boiling point is Δt = i Kbm

Δt = i Kbm

= 2 *0.52* 4.288 = 104.46°C

Therefore the new boiling point is 104.46°C

Example 2: What is the new boiling point prepared by adding 80 g of sodium chloride to 200mL of water? The boiling point constant for water is 0.42°C/m.

Solution:

Given that,

Mass of sodium chloride = 80g

Molecular weight of NaCl is = 58.44

Volume of solution in litres = 200/1000 = 0.200 lit

Boiling point constant Kb is = 0.42°C/m.

Now find molarity of Nacl = no.of moles / volume in lit

= ( mass/ mol.wt ) / volume in lit

= (80/58.44) / 0.200) = 6.844m

Formula for boiling point is Δt = i Kbm

= 2 *0.42* 6.844 = 105.74°C

Therefore the new boiling point is 105.74°C

1. What is meant by boiling point?

The boiling point of a liquid is the temperature at which it starts to change into steam or vapour. For example, the boiling point of water is 100°c.The boiling point of mercury is 356.7°C.

2. How pressure affects boiling point?

The boiling point is reached when the liquid vapour pressure matches the atmospheric pressure. The pressure affects the boiling point of a substance. The pressure increases mean more energy is required for liquids to boil, so highest boiling point.

3. Which has the lowest boiling point?

The chemical element that has the lowest boiling point is Helium. The helium boiling point value is -268.9°C.

4. What is the Importance of Boiling Point?

• 1. The boiling point of organic compounds can give important information about their physical properties and structural characteristics.
• 2. Boiling point helps identify and characterise a compound.
• 3. Boiling point of a chemical is also very important for its storage & transport.