A sample of `2` kg monoatomic helium (assumed ideal ) is taken from `A` to `C` through the process `ABC` and another sample of `2` kg of the same gas is taken through the process `ADC` (seefig). Given molecular mass of helium = `4`.

(i) What is the temperature of helium in each of the states `A ,B , C ` and `D`?
(ii) Is there any way of telling afterwards which sample of helium went through the process `ABC` and which went through the process `ADC`? Write Yes and No.
How much is the heat involved in the process `ABC` and `ADC`?

Answer

3250

Explanation

Number of gram moles of He
`n = m/M = (2xx10^3)/4 = 500`
`V_A = 10m^3 , PA = 5 xx10^4 "N/m"^2`
` :." "T_A = (P_A V_A)/(nR) = ((10)(5xx10^4))/((500 )(8.31))K`
or `T_A = 120.34 K `
Similarly, `V_B = 10m^3, P_B =10 xx10^4 "N/m"^2`
`:." "T_B =((10)(10xx10^4))/((500)(8.31))K" ":." "T_B = 240. 68 K`
`V_C = 20m^3, PC = 10 xx10^4 "N/m"^2 " ":." "T_C = ((20)(10xx10^4))/((500)(8.31))K`
`T_C =481.36 K" and " V_D = 20m^3, PD = 5xx10^4"N/m"^2`
`:." "V_D = ((20)(5xx10^4))/((500)(8.31))K`
`T_D = 240.68 K`