Find the change in entropy when 1.25 kg of steam at 100OC condenses and cools to 50OC. Can someone please give me a hint how to solve it :<
To find the change in entropy when steam condenses and cools, you can utilize the equation:
ΔS = m * (s2 - s1)
where ΔS is the change in entropy, m is the mass of the substance, and s2 and s1 are the specific entropies of the substance at the final and initial states, respectively.
To solve this problem, you need the specific entropy values for steam at 100°C and 50°C. These values can be found in steam tables or thermodynamic property databases.
Once you have the specific entropy values, you can substitute them into the equation along with the mass of the steam to find the change in entropy.
To solve this problem, you will need to use the formula for entropy change:
ΔS = m * (S2 - S1)
where ΔS is the change in entropy, m is the mass of the substance, S2 is the final entropy, and S1 is the initial entropy.
To find the change in entropy when steam condenses and cools, you will need to consider two processes: the phase change from steam to liquid (condensation) and the temperature change from 100°C to 50°C.
Here are the steps to solve the problem:
1. Find the entropy of steam at 100°C and liquid water at 100°C.
- Look up the entropy values for steam (S1) and liquid water (S2) at 100°C from a thermodynamic table.
- Subtract S2 from S1 to find the entropy change during condensation.
2. Find the entropy of liquid water at 50°C.
- Look up the entropy value for liquid water (S1) at 50°C from a thermodynamic table.
- Subtract S1 from the result in step 1 to find the entropy change during cooling.
3. Calculate the mass of the steam.
- Given that the mass of the steam is 1.25 kg, use this value for m in the entropy change formula.
4. Plug the values into the entropy change formula and calculate ΔS.
- Substitute the mass of the steam, the entropy changes from steps 1 and 2, and calculate the change in entropy.
That's it! You should be able to calculate the change in entropy using these steps.