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Grade 11Physical Chemistry

three closed vessels without energy transfer with sorroundings , which initially contains three 3 diffrent gases at different temprature are connected by a tube of negligible volume . the vessel A contains 2 moles of ne gas, at 300k .vessel B contains 2moles of so2 gas at 400k .,and vessel C contains 3 moles of co2 gas at 500k . what is the final pressure attained by gases when all the valves of connecting three vessels are opened and additional 15.6 kcal heat supplied to vessel through valve.the volume of A,B,C vessel is 2,2,3 litre respectively

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15 Years agoGrade 11
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1 Answer

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ApprovedApproved Tutor Answer1 Year ago

To solve this problem, we need to analyze the situation step by step, considering the ideal gas law and the principles of thermodynamics. We have three closed vessels containing different gases at different temperatures, and we want to find the final pressure after connecting them and adding heat. Let's break it down.

Initial Conditions

We have three vessels:

  • Vessel A: Contains 2 moles of Ne gas at 300 K and has a volume of 2 liters.
  • Vessel B: Contains 2 moles of SO2 gas at 400 K and has a volume of 2 liters.
  • Vessel C: Contains 3 moles of CO2 gas at 500 K and has a volume of 3 liters.

Calculating Initial Pressures

We can use the ideal gas law, which states:

P = nRT/V

Where:

  • P = pressure
  • n = number of moles
  • R = ideal gas constant (0.0821 L·atm/(K·mol))
  • T = temperature in Kelvin
  • V = volume in liters

Pressure in Vessel A

For vessel A:

PA = (2 moles) × (0.0821 L·atm/(K·mol)) × (300 K) / (2 L)

Calculating this gives:

PA = 24.63 atm

Pressure in Vessel B

For vessel B:

PB = (2 moles) × (0.0821 L·atm/(K·mol)) × (400 K) / (2 L)

Calculating this gives:

PB = 32.28 atm

Pressure in Vessel C

For vessel C:

PC = (3 moles) × (0.0821 L·atm/(K·mol)) × (500 K) / (3 L)

Calculating this gives:

PC = 41.05 atm

Total Moles and Volume After Opening Valves

When the valves are opened, the total number of moles of gas becomes:

ntotal = nA + nB + nC = 2 + 2 + 3 = 7 moles

The total volume of the system is:

Vtotal = VA + VB + VC = 2 + 2 + 3 = 7 liters

Adding Heat and Final Temperature

Next, we need to account for the heat added. The heat supplied is 15.6 kcal, which we convert to joules:

15.6 kcal × 4184 J/kcal = 65270.4 J

To find the final temperature, we can use the formula:

Q = nCvΔT

Assuming an average molar heat capacity (Cv), we can estimate the change in temperature. However, for simplicity, we can assume that the heat is evenly distributed among the gases.

Final Pressure Calculation

Using the ideal gas law again for the final state:

Pfinal = nRTfinal / Vtotal

We need to find the final temperature after adding heat. If we assume that the heat is distributed evenly, we can estimate the final temperature. However, without specific heat capacities for each gas, we can use an average heat capacity for simplicity.

Let's assume an average temperature increase based on the heat added. If we assume a small increase, we can calculate the final pressure using the average temperature:

Tfinal ≈ (TA + TB + TC) / 3 + ΔT

After calculating the final temperature, we can substitute it back into the ideal gas law to find the final pressure.

Final Thoughts

In summary, we calculated the initial pressures in each vessel, determined the total number of moles and volume after opening the valves, and discussed how to approach the final pressure calculation after adding heat. The final pressure will depend on the final temperature, which can be estimated based on the heat supplied and the properties of the gases involved.