Chemistry

posted by .

I really don't get this. The calculations shown don't make sense.

Demonstrate that work is not a state function by calculating the work involved in expanding a gas from an initial state of 1.00: and 10.0atm of pressure to (a) 10,0 L and 1.0 atm pressure. (b) 5.00L and 2.00 atm and then to 10,0L and 1.00 atm pressure.


Solution
(a) w=-PV = -(1.00atm(10.0L-5.0L)
= -9.0L atm

(b) w=-PV = -(2.00atm)(5.0L-1.00L)-(0.0L- 5.0L)
=-13.0L atm

I don't see how the calculations correlate with what was given in the question.

Can someone please explain to me? Thanks!

  • Chemistry -

    Referring to Part (b)
    ••Assume [PV] is a state function:
    PV = (5 L)(2 atm) = 10 L.atm
    PV = (10L)(1 atm) = 10 L.atm
    ∆(PV) = [PV]2 - [PV]1 = 10L.atm - 10L.atm = 0 work (not true)

    ••Actual work = -P∆V which could not be equal to 0 since P is not 0, and ∆V = is not 0. P varies from 2 atm to 1 atm., and ∆V = 5L.

    For more in depth information on this check:
    http://www.chem.arizona.edu/~salzmanr/480a/480ants/pvwork/pvwork.html

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chemistry

    Consider a sample containing 2.00 mol of a monatomic ideal gas that undergoes the following changes from State A to State D: State A PA=10.5atm, VA=10.00L State B PB=10.5atm, VB=5.00L State C PC=24.5atm, VC=5.00L State D PD=24.5atm, …
  2. Physics

    Suppose a monatomic ideal gas is changed from state A to state D by one of the processes shown on the PV diagram. Find the total work done on the gas if it follows the constant temperature path A-C followed by the constant pressure …
  3. chemistry

    A quantity of 0.020 mole of a gas initially at 0.050 L and 20 degrees Celsius undergoes a constant-temperature expansion until its volume is 0.59 L. Calculate the work done (in joules) by the the gas if it expands (b) pressure of 0.20 …
  4. Chemistry

    A quantity of 0.020 mole of a gas initially at 0.050 L and 20 degrees Celsius undergoes a constant-temperature expansion until its volume is 0.59 L. Calculate the work done (in joules) by the the gas if it expands (b) pressure of 0.20 …
  5. physics

    Consider 3 liters of an ideal (monatomic) gas at a pressure of 34 atm and a temperature of 356K. Call this state of the system A. Using the ideal gas law, calculate the number of moles of gas present in the system. 3.49 The temperature …
  6. CHEMISTRY

    Consider the following cyclic process carried out in two steps on a gas. Step 1: 41. J of heat is added to the gas, and 20. J of expansion work is performed. Step 2: 60. J of heat is removed from the gas as the gas is compressed back …
  7. Gas Law Chemistry

    I need help on these two questions: If a certain gas occupies a volume of 16L when the applied pressure is 8.0atm , find the pressure when the gas occupies a volume of 4.0L . A certain gas is present in a 12.0L cylinder at 4.0atm pressure. …
  8. Physics AP

    An ideal monatomic gas expands isobarically from state A to state B. It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A. How much work is done on …
  9. physics

    The internal energy of a system changes because the system gains 180 J of heat and performs 338 J of work. In returning to its initial state, the system loses 111 J of heat. During this return process, what work is involved?
  10. physics

    An ideal gas is in equilibrium at initial state with temperature T=137oC, pressure P = 0.75Pa and volume V = 0.75 m3. If there is a change in state in which the gas undergoes an isothermal process to a final state of equilibrium during …

More Similar Questions