Boiling Point Elevation Calculator
🧪 Solutions & Molarity. Use the Boiling point elevation formula to find rise δt_b, van 't hoff factor i, k_b, molality: pick the value you want, type the others, and the answer updates as you go.
Water: K_b = 0.512 °C·kg/mol. NaCl splits into 2 ions, so i = 2.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Rise ΔT_b | °C |
| van 't Hoff factor i | no unit |
| K_b | °C·kg/mol |
| Molality | mol/kg |
Worked example
Find the rise δt_b when van 't Hoff factor i = 2, K_b = 0.512 °C·kg/mol, Molality = 1 mol/kg.
Using Δ Tb = i Kb m: Rise ΔT_b = 1.024 °C.
Frequently asked questions
What is the formula for Boiling point elevation?
Δ Tb = i Kb m. Water: K_b = 0.512 °C·kg/mol. NaCl splits into 2 ions, so i = 2.
What do the letters stand for, and what units are used?
Rise ΔT_b in °C, van 't Hoff factor i, K_b in °C·kg/mol, Molality in mol/kg.
How do you calculate rise δt_b?
Put the values into Δ Tb = i Kb m. For example, with van 't Hoff factor i = 2, K_b = 0.512 °C·kg/mol, Molality = 1 mol/kg, rise δt_b = 1.024 °C.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (rise δt_b, van 't hoff factor i, k_b, molality) and fill in the others: it rearranges the formula for you.
