ThermoPhysics

During the compression stroke of a certain gasoline engine, the pressure increases from 1.00 atm to 20.5 atm. The process is adiabatic and the air–fuel mixture behaves as a diatomic ideal gas.
(a) By what factor does the volume change?
Vfinal = Vinitial
(b) By what factor does the temperature change?
Tfinal = Tinitial
Assume the compression starts with 0.016 mole of gas at 26.5°C.
(c) Find the value of Q that characterizes the process.
J
(d) Find the value of ΔEint that characterizes the process.
J
(e) Find the value of W that characterizes the process.
J

  1. 👍 0
  2. 👎 0
  3. 👁 215
  1. Adiabatic index
    γ=(i+2)/i=(5+2)/5= 1.4.
    (a) p₁(V₁)^γ=p₂(V₂)^γ
    V₁/V₂ =( p₂/p₁)^(1/ γ)=20.5^(1/1.4)=
    =20.5^(0.714)=8.65.

    (b) (p₂/p₁)^(γ-1) = (T₂/T₁)^γ
    (T₂/T₁) =((p₂/p₁)^[(γ-1/γ)]=
    =20.5^(0.2857)=2.37.

    (c) An adiabatic process is a process occurring without exchange of heat of a system with its environment =>
    Q=0.

    ν =0.016 mol
    T₁=273+26.5 = 299.5 K,
    T₂/T₁=2.37,
    T₂=2.37•T₁=2.37•299.5=710 K.

    (d,e) ΔE=- W
    W= ν•{R/(γ-1)}(T₁-T₂) =
    =0.016•8.31(299.5-710)/(1.4-1) =
    = - 136.45 J
    ΔE=136.45 J

    1. 👍 0
    2. 👎 0
    posted by Elena

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics (forgot to post this question #2)

    During the compression stroke of a certain gasoline engine, the pressure increases from 1.00atm to 20.0atm. If the process is adiabatic and the fuel air mixture behaves a a diatomic ideal gas a) by what factor does the volume

    asked by ~christina~ on March 26, 2008
  2. physics

    Stuck on this homework problem, any help would be appreciated. Thank you!! A truck has 5.9L diesel engine in it. 5.9L of the overall displacement in 6 cylinders each 102mm bore (diameter) and 120mm stroke (length). Engine operates

    asked by xyz on May 5, 2014
  3. Chem

    During which stroke of a four-stroke internal combustion engine is the system's temperature raised because work is done to the gases? A. Compression stroke B. Power stroke C. Exhaust stroke D. Intake stroke

    asked by Jessie on August 18, 2016
  4. chemistry

    During which stroke of a four-stroke internal combustion engine is work done to the system of gases? A. Exhaust stroke B. Intake stroke C. Compression stroke D. Power stroke

    asked by Cortney on March 23, 2015
  5. chemistry

    1. Ideal gas particles: A. have no mutual attraction and no individual volume. B. have no mass or volume. C. have no odor and no color. D. have no density and do not form bonds. Is it A? 2. Why does the density of gas in a hot air

    asked by Cortney on March 18, 2015
  6. math

    A four-cylinder engine has a bore of 90mm and a stroke of 100mm. The clearance volume of each cylinder is 0.065 L. Assuming compression starts at the bottom of the stroke, determine: (a) the capacity of the engine (b) the

    asked by Alice on September 13, 2016
  7. Physics

    A Jaguar XK8 convertible has an eight-cylinder engine. At the beginning of its compression stroke, one of the cylinders contains 499 cm ^ 3 of air at atmospheric pressure (1.01\times 10^5 Pa}) and a temperature of 27.0 degrees C.

    asked by Natalie on November 12, 2012
  8. Integrated Physics and Chemistry

    In a four-stroke internal combustion engine, the gas vapor/air mixture is pressurized during the ____ stroke. compression power intake exhaust

    asked by jesssssss on May 4, 2011
  9. Chemistry

    The air in a cylinder of a diesel engine occupies 1.00 L at 30 degrees celsius and 1.00 atm. What is the pressure in the cylinder when the air is compressed to 0.0714 L (14:1 compression ratio) and heats to 480 degrees celsius?

    asked by Eve on May 22, 2016
  10. AP Physics B (chemistry bit)

    I think I'm doing this wrong In an internal combustion engine, air at atmospheric pressure and a temperature of about 20 degrees celcius is compressed in the cylinder by a piston to 1/9 of its original volume (compression ratio =

    asked by AP Physics B (chemistry bit) on November 15, 2009

More Similar Questions