Let's analyze the phase envelope chart for the 30.02% Methane mixture (bolded curve labeled "3" in the legend) and answer the questions based on the provided graph: ### 1. **Bubble-point pressure at -110°F** - Find -110°F on the x-axis (Temperature). - Move up vertically until you hit the left boundary (bubble-point curve) of the 30.02% Methane envelope. - The corresponding y-value (Pressure) is **about 320 psia**. --- ### 2. **Critical temperature** - The critical point is at the top of the phase envelope. - For the 30.02% Methane mixture, it's approximately **45°F**. --- ### 3. **Critical pressure** - At the critical point, from the y-axis, it's about **865 psia**. --- ### 4. **Dew-point temperature at 800 psia** - Find 800 psia on the y-axis. - Move horizontally until you hit the right boundary (dew-point curve) of the 30.02% envelope. - The corresponding x-value (Temperature) is **about 27°F**. --- ### 5. **Bubble-point temperature at 500 psia** - Find 500 psia on the y-axis. - Move horizontally until you hit the left boundary (bubble-point curve) of the envelope. - The corresponding temperature is **about -68°F**. --- ### 6. **Cricondentherm** - The maximum temperature on the envelope's right boundary. - About **55°F**. --- ### 7. **Cricondenbar** - The maximum pressure on the envelope's upper boundary. - About **900 psia**. --- ### 8. **Dew-point pressure at -20°F** - Find -20°F on the x-axis. - Move up to the right boundary (dew-point curve). - The corresponding pressure is **about 850 psia**. --- ### 9. **Bubble-point pressure at -100°F** - Find -100°F on the x-axis. - Move up to the left boundary (bubble-point curve). - The corresponding pressure is **about 380 psia**. --- ### 10. **Temperature range for retrograde gas** - Retrograde condensation occurs between the cricondentherm and the critical temperature. - Approximate range: **0°F to 55°F**. --- ### 11. **A point represented by 20°F and 1000 psia represents what fluid type** - 1000 psia is outside the phase envelope, so this is a **single-phase gas**. --- ### 12. **A point represented by 0°F and 600 psi represents what fluid type** - 0°F and 600 psi is inside the phase envelope, which represents a **two-phase region (gas + liquid)**. --- If you need more specific answers or explanation for any part, let me know!

Certainly! Here's a detailed explanation of each question based on the phase envelope chart for the 30.02% Methane mixture, along with the final answers: --- ### **Understanding the Phase Envelope Chart** The phase envelope chart shows the relationship between temperature and pressure for a hydrocarbon mixture. It indicates regions where the mixture exists as a vapor (gas), liquid, or a mixture of both. The envelope is bounded by the bubble-point and dew-point curves: - **Bubble-point curve:** The boundary where the mixture begins to condense into liquid as pressure increases at a given temperature. - **Dew-point curve:** The boundary where vapor begins to condense into liquid as temperature decreases at a given pressure. - **Cricondentherm:** The highest temperature at which liquid and vapor coexist. - **Cricondenbar:** The highest pressure at which liquid and vapor coexist. - **Critical point:** The temperature and pressure beyond which the fluid is a supercritical fluid. --- ### **1. Bubble-point pressure at -110°F** **Explanation:** At a fixed temperature of -110°F, to find the bubble-point pressure, locate -110°F on the x-axis. Then move vertically upward until you intersect the **bubble-point curve** of the 30.02% methane mixture. **Observation:** From the chart, this intersection occurs around **320 psia**. **Final Answer:** **Approximately 320 psia** --- ### **2. Critical temperature** **Explanation:** The critical temperature is the highest temperature at which the mixture can exist as a liquid-vapor equilibrium. It is located at the top of the phase envelope, where the bubble and dew curves meet. **Observation:** The topmost point of the envelope for the mixture is approximately **45°F**. **Final Answer:** **Approximately 45°F** --- ### **3. Critical pressure** **Explanation:** This is the pressure at the critical point, where the phase boundary disappears and the fluid becomes supercritical. **Observation:** At the critical point (top of the envelope), the pressure is about **865 psia**. **Final Answer:** **Approximately 865 psia** --- ### **4. Dew-point temperature at 800 psia** **Explanation:** At a pressure of 800 psia, locate this pressure on the y-axis, then draw a horizontal line across until it intersects the **dew-point curve** of the mixture. **Observation:** The intersection point corresponds to roughly **27°F**. **Final Answer:** **Approximately 27°F** --- ### **5. Bubble-point temperature at 500 psia** **Explanation:** At 500 psia, find this pressure on the y-axis, then move horizontally to intersect the **bubble-point curve**. **Observation:** This occurs at approximately **-68°F**. **Final Answer:** **Approximately -68°F** --- ### **6. Cricondentherm** **Explanation:** The cricondentherm is the highest temperature at which the mixture can exist as a two-phase (liquid + vapor) mixture, located at the top of the right boundary curve. **Observation:** It is approximately **55°F**. **Final Answer:** **Approximately 55°F** --- ### **7. Cricondenbar** **Explanation:** The cricondenbar is the highest pressure at which the liquid-vapor coexistence occurs, located at the top of the upper boundary curve. **Observation:** This is about **900 psia**. **Final Answer:** **Approximately 900 psia** --- ### **8. Dew-point pressure at -20°F** **Explanation:** At -20°F, locate this temperature on the x-axis, then move vertically upward to intersect the **dew-point curve**. **Observation:** The pressure at this point is around **850 psia**. **Final Answer:** **Approximately 850 psia** --- ### **9. Bubble-point pressure at -100°F** **Explanation:** At -100°F, locate this temperature, then move vertically upward to intersect the **bubble-point curve**. **Observation:** The corresponding pressure is approximately **380 psia**. **Final Answer:** **Approximately 380 psia** --- ### **10. Temperature range for retrograde gas** **Explanation:** Retrograde condensation occurs in the temperature range between the **cricondentherm** and the **critical temperature** where the gas can condense upon pressure reduction or temperature change. **Observation:** This range is roughly **0°F to 55°F**. **Final Answer:** **Approximately 0°F to 55°F** --- ### **11. A point represented by 20°F and 1000 psia** **Explanation:** - 20°F is within the temperature range of the phase envelope. - 1000 psia is above the **cricondentherm** (55°F) and **cricondenbar** (900 psia), meaning the pressure exceeds the maximum for two-phase coexistence. **Interpretation:** This point is **outside the phase envelope**, indicating the mixture exists as a **single-phase gas** at this temperature and pressure. **Final Answer:** **Single-phase gas (supercritical or dry gas)** --- ### **12. A point represented by 0°F and 600 psi** **Explanation:** - 0°F is within the envelope. - 600 psia is below the bubble-point pressure at 0°F (~600 psia), placing it inside the two-phase region. **Interpretation:** This point lies **inside the phase envelope**, indicating a **two-phase mixture** (liquid + vapor). **Final Answer:** **Two-phase (gas + liquid)** --- ### **Summary of Final Answers:** | Question | Final Answer | |------------|--------------| | 1. Bubble-point pressure at -110°F | **~320 psia** | | 2. Critical temperature | **~45°F** | | 3. Critical pressure | **~865 psia** | | 4. Dew-point temperature at 800 psia | **~27°F** | | 5. Bubble-point temperature at 500 psia | **~-68°F** | | 6. Cricondentherm | **~55°F** | | 7. Cricondenbar | **~900 psia** | | 8. Dew-point pressure at -20°F | **~850 psia** | | 9. Bubble-point pressure at -100°F | **~380 psia** | | 10. Temperature range for retrograde gas | **0°F to 55°F** | | 11. Fluid at 20°F, 1000 psia | **Single-phase gas** | | 12. Fluid at 0°F, 600 psia | **Two-phase (gas + liquid)** | --- If you'd like, I can provide further explanation on any specific calculation or concept!