Hi,

Answer:

Final pressure in each flask is 0.572 atm.

Explanation:

Given Data:

Two flasks of equal VOLUME are at initial TEMPERATURE 27°C, initial pressure 0.5 atm and contains 0.35 moles of H₂.

To find: final pressure in each flask

Let the two flasks be “a” & “b”. Also, let flask “a” be immersed in a bath at temperature, Ta = 127°C = 127 + 273.15 = 400.15 K and flask “b” remains the same as initial temperature i.e., temperature, Tb = 27°C + 273.15 = 300.15 K . No. of moles in flask a and b be “na” & “nb” respectively.

Using Ideal Gas Law for the combined system INITIALLY, we have

PV = nRT

Or, 0.5 * 2V = 0.35 * R * 300.15 …[∵ both the flasks have the same volume]

Or, V = 105.052 R ….. (i)

The final pressure in both the flask Pa and Pb will be same i.e., Pa = Pb = P and also Va = Vb = V.  

For flask a :

Pa * Va = na * R * Ta

Or, P * V = na * R * Ta

Or, P * 105.052R = na * R * 400.15 ….. [ value of V from (i)]

Or, na = 0.262P ….. (ii)

For flask b:

Pb * Vb = nb * R * Tb

Or, nb = (Pb Vb) / (R Tb)

Or, nb = (P * 105.052 R) / (R * 300.15 )

Or, nb = 0.349P ….. (iii)

We know,  

TOTAL no.of moles initially = na + nb

Substituting values of na and nb from (ii) & (iii)

Or, 0.35 = 0.262P + 0.349P

Or, 0.35 = 0.611P

Or, P = 0.35/0.611 = 0.572 atm

Hence, the final pressure P = Pa = Pb = 0.572 atm.

Hope this is helpful!!!!