What happens to the temperature and pressure of a pure substance as it undergoes a phase change from saturated liquid to saturated vapor?
Explanation
A key concept in phase-change processes is that for a pure substance, boiling or condensation occurs at a constant temperature (the saturation temperature) and constant pressure (the saturation pressure).
Other questions
According to the definition provided, what is a pure substance?
What is pressure defined as in the context of thermodynamics?
What is the relationship between absolute pressure (P_abs), atmospheric pressure (P_atm), and gauge pressure (P_gauge)?
A piston-cylinder device contains a gas. The piston has a mass of 10 kg and a diameter of 20 cm. The atmospheric pressure is 101.325 kPa. What is the absolute pressure of the gas in the cylinder, assuming the piston is in static equilibrium and gravitational acceleration is 9.8 m/s^2?
What fundamental principle, which forms the basis for temperature measurement, is known as the zeroth law of thermodynamics?
How is the absolute temperature in Kelvin (K) related to the temperature in Celsius (C)?
What is the relationship between density (rho) and specific volume (v)?
A container has two sections separated by a membrane. Section A contains 0.5 kg of air in a volume of 0.75 m^3. Section B contains air with a density of 0.6 kg/m^3 in a volume of 0.5 m^3. If the membrane breaks and the air mixes, what is the specific volume of the air at the final uniform state?
Which property is defined as the sum of the internal energy (U) and the flow work (PV) of a fluid?
What does entropy represent in a thermodynamic system?
On a Pressure-Temperature (P-T) phase diagram, what is the point at which the solid, liquid, and vapor phases of a substance coexist in equilibrium?
What happens to a substance at a pressure lower than its triple point pressure as it is heated?
Based on the P-T diagram for CO2 provided in the chapter, what is the lowest pressure at which liquid CO2 can exist?
In a T-v or P-v diagram for a pure substance, what does the region to the left of the saturated liquid line represent?
What does the quality (x) of a saturated liquid-vapor mixture represent?
Which equation correctly calculates the specific volume (v) of a saturated liquid-vapor mixture with quality (x)?
When determining the properties of a fluid, if both temperature (T) and pressure (P) are given, what is the first step according to the procedure in the chapter?
What is the state of water at a temperature of 150 degrees Celsius and a pressure of 100 kPa?
Ammonia is in a state where its temperature is 0 degrees Celsius and its specific volume is 0.2 m^3/kg. What is the state of the ammonia?
Ammonia at 0 degrees Celsius has a specific volume of 0.2 m^3/kg. Given that at this temperature, v_f = 0.001566 m^3/kg and v_g = 0.289297 m^3/kg, what is the quality (x) of the mixture?
Refrigerant R134a has a specific enthalpy of 420 kJ/kg at a temperature of 20 degrees Celsius. Given that the specific enthalpy of saturated vapor (h_g) at 20 C is 409.75 kJ/kg, what is the state of the R134a?
If thermodynamic tables are not available for a compressed liquid, what approximation can be used to find its properties?
What is the primary characteristic of an extensive property?
Which of the following is an example of an intensive property?
According to the chapter, how are properties like specific internal energy (u), specific enthalpy (h), and specific entropy (s) determined for thermodynamic tables, given they cannot be measured directly?
On a Pressure-specific volume (P-v) diagram, what do the lines of constant temperature (isotherms) look like in the superheated vapor region?
What is the defining characteristic of a substance in a supercritical state?
What is the process called when a substance transitions directly from a solid to a vapor phase?
To fix the state of a pure substance that is a single-phase fluid (compressed liquid or superheated vapor), how many independent, intensive properties are required?
To fix the state of a pure substance that is a saturated two-phase mixture, what information is required?
What is the specific internal energy (u) associated with?
What does the specific enthalpy (h) represent for a unit mass of a substance?
On a P-T diagram, the curve separating the liquid and vapor phases is called the:
What is a quality (x) of zero equivalent to?
When are linear interpolations often used with thermodynamic tables?
In the linear interpolation formula y = y0 + (x - x0) * (y1 - y0) / (x1 - x0), what does the point (x, y) represent?
Using interpolation for R134a at 20 degrees Celsius, given P1=100 kPa with h1=420.31 kJ/kg and P2=150 kPa with h2=419.33 kJ/kg, what is the approximate pressure P for a specific enthalpy h=420 kJ/kg?
Why is it important to use thermodynamic tables from the same source for calculations in a thermodynamic analysis?
What is the key distinction between specific volume (v) and volume (V)?
On a Temperature-specific volume (T-v) diagram, the curve separating the saturated liquid-vapor region from the superheated vapor region is called the:
A substance has a quality (x) of 1. What is its state?
For a saturated liquid-vapor mixture, which formula is used to calculate the specific internal energy (u)?
What is another common name for a compressed liquid?
According to the provided P-T diagram for CO2, what phase is CO2 in at a pressure of 100 bar and a temperature of 275 K?
What is the key takeaway about the internal energy of a substance like water when its temperature increases from 20 to 40 degrees Celsius?
The total stored energy (E) of a system is defined as the sum of which components, assuming no magnetic, electric, or surface tension effects?
What is the common SI unit for specific entropy (s)?
If a fluid is determined to be a compressed liquid because its pressure P is greater than the saturation pressure P_sat at a given temperature T, what is the next step according to the flowchart for determining properties?
In a T-v diagram, where do the saturated liquid line and the saturated vapor line meet?