Practice Problem: Isothermal Process An ideal gas is initially in a state that corresponds to point 1 on the graph above, where it has pressure p1, volume V1, and temperature T1. The gas undergoes an isothermal process represented by the curve shown, which takes it to a final state 3 at temperature T3. If T2 and T4 are the temperatures the gas would have at points 2 and 4, respectively, which of the following relationships is true? (A) T1 < T3 (B) T1 < T2 (C) T1 < T4 (D) T1 = T2 (E) T1 = T4 Four Types of Processes Isobaric Pressure Isochoric (isovolumetric) Isothermal- Adiabatic- nothing stays the same –Constant Volume stays the same Temperature stays the same Pressure is constant Pressure changes Temperature does not change Happens very fast. No enough time for energy to come in from outside the Volume increases Volume is constant Internal Energy does not change system. All energy comes from internal energy. Q=0 W=P∆V W= 0J ∆U=0 Q=W ∆U=-W ∆U=Q What the Graph Looks Like: What the Graph Looks Like: What the Graph Looks Like: What the Graph Looks Like: Real World Example: Real World Example: Real World Example: Real World Example:
Practice Problem: Isothermal Process An ideal gas is initially in a state that corresponds to point 1 on the graph above, where it has pressure p1, volume V1, and temperature T1. The gas undergoes an isothermal process represented by the curve shown, which takes it to a final state 3 at temperature T3. If T2 and T4 are the temperatures the gas would have at points 2 and 4, respectively, which of the following relationships is true? (A) T1 < T3 (B) T1 < T2 (C) T1 < T4 (D) T1 = T2 (E) T1 = T4 Four Types of Processes Isobaric –Constant Pressure Isochoric (isovolumetric) Volume stays the same Isothermal- Temperature stays the same Adiabatic- nothing stays the same Pressure is constant Volume increases W=P∆V What the Graph Looks Like: Real World Example: Pressure changes Volume is constant W= 0J ∆U=Q What the Graph Looks Like: Real World Example: Temperature does not change Internal Energy does not change ∆U=0 Q=W What the Graph Looks Like: Real World Example: Happens very fast. No enough time for energy to come in from outside the system. All energy comes from internal energy. Q=0 ∆U=-W What the Graph Looks Like: Real World Example: