How do I find out I would evaporate all solvent ( dichloromethane) from mixture with water? I have less than 1500 ppm of dichloromethane in water and want to be sure if I evaporate all that stuff at 160 degrees? I got the feeling that iw would evaporate but need to support it with math . Can anyone help please??
To determine whether you can evaporate all the dichloromethane (DCM) from a mixture with water, you can use a mathematical concept called Raoult's Law. Raoult's Law states that the vapor pressure of a component in a mixture is directly proportional to its mole fraction in the liquid phase.
Here's how you can use Raoult's Law to estimate the evaporation of DCM from the mixture:
1. Calculate the mole fraction of DCM in the mixture:
- Convert the concentration of 1500 ppm to a mole fraction by dividing it by 1 million. In this case, 1500 ppm = 0.0015 (mole DCM / mole total).
2. Determine the vapor pressure of pure DCM at the given temperature:
- Look up the vapor pressure of DCM at 160 degrees Celsius. Let's assume it is P(DCM) = X atmospheres.
3. Calculate the vapor pressure of DCM in the mixture:
- Use Raoult's Law to calculate the vapor pressure of DCM in the mixture. P(DCM mixture) = X * mole fraction of DCM.
4. Compare the vapor pressure of DCM in the mixture to the total atmospheric pressure:
- If the vapor pressure of DCM in the mixture is lower than the total atmospheric pressure (at 160 degrees Celsius), it suggests that DCM will evaporate completely.
Remember that this method assumes ideal behavior, and in practice, there may be other factors affecting the evaporation of DCM, such as non-ideal behavior of the components and potential interactions between DCM and water.
So, to summarize, to determine if you can evaporate all the DCM from the mixture, calculate the vapor pressure of DCM using Raoult's Law and compare it to the total atmospheric pressure at 160 degrees Celsius.