Write an unsteady mass balance on the particle

Assignment Help Chemistry

Reference no: EM131262741

Biotransport Assignment

1. A drug has an equilibrium solubility in water of 0.0025 g cm^-3. The diffusivity of the drug in water is 0.9 x 10^-5 cm2/sec. The drug is made into particles that have a radius of 0.1 cm and these particles have a density of 1.27 g/cm^3. These particles are all of the same size and are gently mixed in water in a stirred vessel. Estimate the length of time in hours (hrs) that it will take for these drug particles to completely dissolve. You can assume that the vessel volume is so large that the concentration of the drug in the bulk liquid is very small in comparison to the drug solubility. Also since the particles are all the same size, the time to dissolve is the same for all the particles. So we can focus on just one particle and write an unsteady mass balance on that particle, i.e., d(ρV)/dt = - 4πR^2 km (Csurface - 0) , where V is the particle volume and equals 4/3 πR^3 .

2. A particular drug is a solid at 300 K and is soluble in water. The equilibrium solubility of the drug in water is 0.005 g cm-3. The MW of the drug is 600. One hundred grams of the drug is made into particles that are 0.2 cm in diameter. The density of the drug particles is 1.05 g cm-3. These particles are then very gently mixed in a stirred vessel containing 100 L of water. After 10 min of mixing, estimate how many grams of the drug have dissolved into the water.

3. A flat plate coated with a layer of a volatile organic material is exposed to a parallel flow of air at 20°C with a free stream air velocity of 5 m sec-1. The length of the flat plate in the direction of flow is 0.5 m. Estimate how long it will take for the average thickness of the volatile organic layer to decrease by 1 mm. The saturation concentration of the organic material in air at these conditions is 1.85 × 10-9 mol cm-3 and its diffusivity in air is 0.068 cm2 sec-1. The density of the volatile organic material as a solid is 1.21 g cm-3 and its MW is 140.2. Also, the kinematic viscosity of air at these conditions is 0.155 cm2 sec-1.

Reference no: EM131262741

Questions Cloud

Appropriate questions based on the recommendations : Discuss a job interview you had at some point. Do you believe the interviewer asked appropriate questions based on the recommendations you have learned in this course?

Federal taxable income and federal income tax liability : Adventure Advertising Agency, Inc. (AAA) is a calendar year, accrual basis C corporation headquartered in St. Paul that provides advertising services to tour and travel companies. What amount of advertising income would AAA report on its financial (b..

Social media and electronic messages : Based on what you've read in the text about how business messages can use Social Media and electronic messages, consider what would be important when trying to reach Digital Natives?

How should you handle this situation : As project leader, you've spoken with these team members about the need to write clearer messages, but they respond that careful planning and writing defeats the whole purpose of instant messaging. How should you handle this situation?

Write an unsteady mass balance on the particle : So we can focus on just one particle and write an unsteady mass balance on that particle, i.e., d(ρV)/dt = - 4πR^2 km (Csurface - 0) , where V is the particle volume and equals 4/3 πR^3 .

Brainstorming techniques : Using the brainstorming techniques, describe it thoroughly, and then provide an example of when this technique would work effectively. You can either use an example from a decision that you have made in your past, or come up with a fictional scena..

Define the decision variables : Formulate a linear programming model for this investment problem. Define the decision variables. Determine the objective function. What does it represent

Proposal of a topic of information technology : Word Limit - Minimum 5 pages, single-spaced, Font Times Roman and Font size 12. References should be given in APA style. A term paper proposal of a Topic of Information technology and it's role in healthcare development. The topic must address the..

Relate to power and politics : For this assignment you will be continuing to write about your own workplace experiences as they relate to power and politics. Think of one of the largest political battles you witnessed or were apart of during your career, and think carefully abo..

User Account

All Pages