Question

220g of Co2 are heated from 27 C - 527C at a constant pressure 1 atm and then compressed isothermally to 100atm calculate the energy absorbed in K.cal Assume Ideal Behaviour (cp=5 cal deg^-1 mol^-1)

Answer 1

@Vincent-Lyon.Fr @akash123 @Carl_Pham

Answer 2

\[\Delta U = W + Q\]

We have to Find Q right ?

Answer 3

Or Is there any other Way to Appraoch This,,,,,)

Answer 4

yes...u have to do this only...calculate work done and change in internal energy

Answer 5

\[\Delta U = nCv \Delta T\]

Answer 6

But i am Confussed Hw to Find Work..)

Answer 7

work done in isothermal process
w= 2.303 RT log(v2/v1)

Answer 8

use w= integral of Pdv
substitute pp from pv=nRT, u'll get the formula for work done in isothermal process.

Answer 9

But V2 and V1.... ???

Answer 10

use pv=n RT

Answer 11

w= 2.303 RT log(p1/p2).???

Answer 12

yes

Answer 13

P1 = 1 P2 = 100

Answer 14

T = 527 C

Answer 15

wait...there r two parts in this Q

Answer 16

in 1st part...it's isobaric process
so simply work done=p(v2-v1)

Answer 17

2nd process is isothermal one

Answer 18

so total work done= w(isobaric)+ w(isothermal)

Answer 19

Ok....For Isothermal.... T= 527....and P1 = 1 P2 =100

Answer 20

yes

Answer 21

use pv=nRT for finding v1 and v2 in the isobaric process.

Answer 22

For..Lemme Try...and will Inform u...) thxxx....

Answer 23

fine...:)

Answer 24

Lol....i got 15.4 K. cal...But the answer shuld be 19.35 K. cl @akash123

Answer 25

Can u check..) pLzzz

Answer 26

U hv calculated total work done only...but u have to calculate change in internal energy also.

Answer 27

du = n c(v) dT

Answer 28

I have Done...that too...

Answer 29

Is Cv = 3

Answer 30

what did u use for c(v)?
c(v) =1/2 f R
f is the degree of freedom
so CO2 is a triatomic
so how many degree of freedom for CO2?

Answer 31

Cp - Cv = R

Cp - R = Cv

Answer 32

R=~2

Answer 33

but how did u come to know the value of c(v) without knowing f?

Answer 34

Cp is Given..)

Answer 35

Meyar"s Relation cp-cv=R

Answer 36

but u know c(p)?

Answer 37

oh...sorry...den u r right.

Answer 38

then for isothermal...change in internal energy=0
u have to calculate only for isobaric process....how much u got?

Answer 39

5000 Cal.

Answer 40

P V1 = nRT

V1 = 5 * 2 * 300

Answer 41

and w(isobaric) and w(isothermal)?

Answer 42

look for the units carefully...

Answer 43

for ex
V1 = 5 * 2 * 300
p--atm
R---cal/mol/K

Answer 44

so u'll get V in cal/atm

Answer 45

For an ideal gas U depends only on T via the energy equation of state, U = C_v NRT, and you can use C_V = C_p - R here since you're given C_p. I don't see a need to calculate the work and heat.