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A] reversible B] irreversible

A cylinder containing an ideal gas is heated at constant pressure from 300K to 350K by immersion in a bath of hot water. Is this process reversible or irreversible?. A] reversible B] irreversible. What is the work done by the gas in the reversible isothermal expansion shown?. A] p 0 V 0 ln(2)

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A] reversible B] irreversible

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  1. A cylinder containing an ideal gas is heated at constant pressure from 300K to 350K by immersion in a bath of hot water. Is this process reversible or irreversible? A] reversible B] irreversible

  2. What is the work done by the gas in the reversible isothermal expansion shown? A] p0V0ln(2) B] p0V0 C] 2 p0V0 D] 0 E] none of these What is the heat added, Q?

  3. No change in internal energy, so W=Q= p0V0ln(2).What is the entropy change of the gas? A] p0V0ln(2) B] nRln(2) C] nRln(1/2) D] 0 E] cannot determine S = Q/T for an isothermal process. Use p0V0=nRT along with Q= p0V0ln(2) to find S = nRln(2). What is the entropy change in the hot reservoir which isadding heat to the gas?

  4. What is the entropy change in the hot reservoir which isadding heat to the gas? In a reversible process, S = 0. So the entropy change in the hot reservoir (which is at the same temperature T as the gas) is -nRln(2). Answer C. A] p0V0ln(2) B] nRln(2) C] nRln(1/2) D] 0 E] cannot determine

  5. We showed, for a Carnot cycle, that QH/TH = |Qc|/TC= -Qc/TcWhat is the change in entropy of the gas around the entire Carnot cycle? A] p0V0ln(2) B] nRln(2) C] nRln(1/2) D] 0 E] cannot determine

  6. Any reversible process consists of “adjoining” Carnot cycles. S for adjoining segments cancels. So: Entropy, like Internal Energy, is a “state” variable, and depends only on the state of a system (p, V for a gas). -> You can calculate entropy changes for irreversible processes by taking a reversible path to the same endpoint. Example: free expansion to double the volume. Tf = Ti.

  7. Entropy changes in non-isothermal processes Example 1: heating water Example 2a/b: heating a gas at constant V/p

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