In this problem you will estimate how much gas is lost from a 2 gallon high dens

Question

In this problem you will estimate how much gas is lost from a 2 gallon high density polyethylene (HDPE) can in a year. Assume the walls of the container are 2 mm thick and for simplicity the container is cubic in form. Assume gasoline has a density of 0.7 g/cm3. The Polymer Handbook (Wiley, 3rd Ed., 1989) lists the diffusion coefficient for hexane (assume that is gasoline) as approximately 1x10-8 cm2/s at ambient temperature. When a 1 gram piece of the HDPE (density = 1 g/cm3) is immersed in gasoline for a long time it increases its weight to 1.001 grams. This provides an estimate of the equilibrium concentration of gasoline in contact with the plastic. What percent of the gasoline in the initially full 2 gallon container is lost in a year?

Explanation / Answer

this is the way for nitrogen gasoline has the exact same. 1 Determine the ambient temperature in Kelvin by taking the current temperature in Celsius and adding 273. For example, if the temperature is 25 degrees Celsius, the temperature in Kelvin is 298. 2 Read the change in pressure from the regulator or gauge in units of atmospheres. If your gauge provides a reading in pounds per square inch (PSI), multiply this number by 0.0680 to obtain the pressure in atmospheres. 3 Subtract the current pressure from the pressure at the starting time. Normally, the starting time will be when the tank was first delivered. For example, if the tank was delivered with a pressure of 3 atmospheres and the current pressure is 2.4 atmospheres, the change in pressure is 0.6 atmospheres. 4 Find the volume of the tank in liters, which is usually written on the tank itself. If the volume is given in cubic feet, multiply the volume by 28.31 to determine the volume in liters. 5 Multiply the change in pressure (in atmospheres) by the volume (in liters), and divide this by the product of 0.0821 and the temperature (in Kelvin). This value is the number of moles of nitrogen that have been lost. 6 To approximate the volume of gas that has been used, multiply the number of moles lost by 22.4. At standard temperature and pressure, this is the volume of nitrogen occupied by each mole of nitrogen.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.