What happens when you pass the critical point for a substance?

The liquid expands and becomes less dense until, at the critical point, the densities of liquid and vapour become equal, eliminating the boundary between the two phases. If the average density at the start is too low, all the liquid will evaporate before the critical temperature is reached.

What is isochoric heat capacity?

we derived the specific isochoric heat capacity cv, which tells how much heat has to be added to or removed from a certain amount of substance in order to increase or decrease, respectively, the temperature of the amount of substance by 1 K at isochoric conditions.

What happens when the temperature and pressure of a substance are greater than the critical point?

At temperatures and pressures higher than the critical point, the substance is considered a fluid–something neither gas or liquid.

What is the significance of critical pressure?

For a pure substance, the critical pressure is defined as the pressure above which liquid and gas cannot coexist at any temperature. The critical temperature for a pure substance is the temperature above which the gas cannot become liquid, regardless of the applied pressure.

What is the phase at critical point?

Critical Point – the point in temperature and pressure on a phase diagram where the liquid and gaseous phases of a substance merge together into a single phase. Beyond the temperature of the critical point, the merged single phase is known as a supercritical fluid.

What is isobaric heat capacity?

In thermodynamics, an isobaric process is a type of thermodynamic process in which the pressure of the system stays constant: ΔP = 0. The heat transferred to the system does work, but also changes the internal energy (U) of the system.

What is the work done in an isochoric process give reason?

An isochoric process is one in which the volume is held constant, meaning that the work done by the system will be zero. The only change will be that a gas gains internal energy.

What happens above the critical temperature?

Above the critical temperature, the molecules have too much kinetic energy for the intermolecular attractive forces to hold them together in a separate liquid phase. Instead, the substance forms a single phase that completely occupies the volume of the container.

What is critical temperature critical volume and critical pressure?

The volume of one mole of a gas volume liquefied at critical temperature is known as the critical volume (Vc) while the pressure required to liquefy the gas at critical temperature is called as the Critical pressure (pc).

Why is heat capacity higher at pressure?

Heat capacity at constant pressure is always greater because it includes both internal energy of the system and the boundary work(expansion process). Whereas , at constant volume it only includes the internal energy of the system.

How do you calculate isobaric specific heat capacity?

At constant pressure, δQ = dU + PdV (isobaric process) At constant pressure, heat supplied to the system contributes to both the work done and the change in internal energy, according to the first law of thermodynamics. The heat capacity is called.