4 Basic Thermodynamic Processes Free Online FlashCards

What does a thermodynamic process describe?

A thermodynamic process describes a system changing from one equilibrium state to another.

What equation relates pressure, volume, and temperature for an ideal gas?

For a fixed amount of ideal gas, the ideal-gas law is $pV=nRT$.

What is the first law using work done by the gas as positive?

With $W$ defined as work done by the gas and $Q$ as heat added to it, the first law is $\Delta U=Q-W$.

How is work represented on a pressure–volume diagram?

For a quasi-static process, work is $W=\int_{V_1}^{V_2}p\,dV$, the signed area under the curve on a pressure–volume diagram.

What determines an ideal gas’s internal-energy change?

An ideal gas’s internal energy depends only on temperature. For constant heat capacity, $\Delta U=nC_V(T_2-T_1)$.

How are $C_P$, $C_V$, and $\gamma$ related for an ideal gas?

For an ideal gas, $C_P-C_V=R$, and the heat-capacity ratio is $\gamma=C_P/C_V$.

What is the work in an isobaric ideal-gas process?

At constant pressure, $W=p(V_2-V_1)=nR(T_2-T_1)$.

How is heat transfer calculated for an isobaric process?

For an isobaric process, the heat transfer is $Q=nC_P(T_2-T_1)$.

What are work and heat transfer in an isochoric process?

At constant volume, $W=0$, so $Q=\Delta U=nC_V(T_2-T_1)$.

What happens to $pV$ and internal energy in an isothermal ideal-gas process?

For a fixed amount of ideal gas at constant temperature, $pV=nRT$ remains constant, and $\Delta U=0$.

What are work and heat transfer in a reversible isothermal process?

For a reversible isothermal process, $W=nRT\ln\!\left(\frac{V_2}{V_1}\right)$ and $Q=W$.

What condition defines an adiabatic process?

An adiabatic process has no heat transfer: $Q=0$.