irs
during primary recovery. This problem explores some aspects of this behavior.
Consider the expansion of methane from 300 bars to 50 bars at a constant temperature of 40 C (313 K).
Methane obeys the following equation of state
V =(RT/P)+C+(D/T)
where C = 31 cm3/mol, D = -693cm3K/mole, and R = 83.14bar cm3/mole K. Note that the units of
energy are bar-cm3/mole in this problem. Report your answer in bar-cm3/mole
(a) What is the change in enthalpy during the expansion
(b) What is the change in internal energy?
(c) What is the heat removed?
(d) How much work does the system do during the expansion?
units.
Chemical Equation: Write a generic chemical equation for the dehydration of cobalt (II) chloride ∙ x hydrate (include the state symbols of the reactant and two products). [T2]
Mass of Reactants and Products:
a) Calculate the initial mass of the hydrated cobalt (II) chloride. [T1]
b) Calculate the final mass of the anhydrous cobalt (II) chloride remaining in the cruiio8icible. [T1]
c) Calculate the mass of water given off by the sample of hydrated cobalt (II) chloride. [T1]
Moles of Products:
a) Calculate the moles of anhydrous cobalt (II) chloride remaining in the crucible. [T1]
b) Calculate the moles of water released from the hydrate. {T1]
4. Mole Ratio
a) Create an experimental mole ratio between the b) and a). [T1]
5. Formula of Hydrate: State the chemical formula you have determined for this hydrate.
Round the formula to the closest whole number value for x. [T1]
Discussion/Conclusion Questions: [T6]
Based on the chemical formula of the hydrate, calculate the percentage composition (percent by mass) of the hydrated cobalt (II) chloride. Remember to determine the percentage of each element (Co, Cl, H, and O). [T2]
A possible source of systematic error in this experiment is insufficient heating. Suppose that the hydrate was not completely converted to the anhydrous form. Describe how this would affect: the calculated percent by mass of water and the experimental molecular formula (i.e. would x be higher, lower or the same).
Suppose a student spilled some of the hydrated cobalt (II) chloride. Describe how this would affect the calculated percent by mass of water (would it be higher, lower or the same) and the experimental chemical formula of the hydrate. [T2]
el of the flow in the coating zone x ∈ [0; L], y ∈ [0; h(x)] a lubrication approximation will be developed. If λ >> 1, and if α is close to, but less than 1 the coating zone appears plane. Use the equation of continuity to show by an order of magnitude estimate that |vy| << |vx|. Then state assumptions on flow and pressure field that reduce the Navier- Stokes equation locally to a form, from which the following approximate expression for the x-velocity in the slot for x ∈ [0; L] can be derived:
Se the attached.