The vapor pressure of CCl3 F at 300 K is 856 torr. If 11.5 g of CCl3 F is enclosed in a 1.0-L co

The vapor pressure of CCl3 F at 300 K is 856 torr. If 11.5 g...

The vapor pressure of $\mathrm{CCl}_{3} \mathrm{F}$ at 300 $\mathrm{K}$ is 856 torr. If 11.5 $\mathrm{g}$ of $\mathrm{CCl}_{3} \mathrm{F}$ is enclosed in a $1.0-\mathrm{L}$ container, will any liquid be present? If so, what mass of liquid? 100 atm at $185^{\circ} \mathrm{C} ?$ Make a graph, analogous to the heating curve for water shown in Figure $11.36 .$ Plot pressure versus time during the pressure increase.

Key Concepts

Pressure-Time Graph During Phase Change

When plotting pressure versus time for a system undergoing a phase change under increasing temperature, the graph will exhibit segments where pressure changes gradually interspersed with plateaus. These plateaus correspond to phase transitions where added energy is used for the transition (e.g., from liquid to vapor) rather than increasing the pressure or temperature of the system.

Heating Curve

A heating curve is a graphical representation that plots a state variable—such as temperature or pressure—against time or added heat, showing the phases of a substance. It typically features plateau regions where phase changes occur, indicating periods during which temperature (or pressure in analogous graphs) remains constant as energy is absorbed or released during transitions.

Ideal Gas Law and Phase Calculations

The Ideal Gas Law (PV = nRT) is often used to relate the pressure, volume, temperature, and number of moles of a gas. In the context of phase equilibrium, it helps determine if the vapor phase in a closed system is sufficient to accommodate all of a substance at a given temperature and pressure, thereby indicating whether any liquid remains or if complete vaporization occurs.

Vapor Pressure

Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid phase at a given temperature. It is a crucial concept for understanding whether a liquid will evaporate or condense in a closed system and is determined by the temperature and the intermolecular forces present in the substance.

Phase Equilibrium

Phase equilibrium refers to the state in which the rates of phase transitions (evaporation and condensation) are balanced, maintaining a constant amount of each phase in a closed system. It explains how a substance can exist simultaneously as a liquid and vapor when the vapor pressure is reached.

Transcript

00:01 In order to solve this problem, we need to know about phase diagrams.

00:05 And basically, a phase diagram is a graph that visualizes the three physical states of matter that a substance will become under different pressures and temperatures.

00:20 And so i have a small mockup of the graph in your book.

00:27 The y -axis is pressure.

00:32 Measured in atmospheres, and the x -axis is temperature, measured in degrees celsius.

00:45 And so these three sections are the ranges in which iodine will be a solid, liquid, or a gas.

00:53 So this region right here is when iodine will be a solid, this region is when it would be a liquid, and this region is when it will be a gas.

01:03 Now, we need to know, or rather we want to draw a heating curve, a heating curve like graph for iodine, when it is undergoing, when it is subjected to heat, when it is being heated from 185 degrees celsius, which we see in the graph is about here.

01:36 And just draw a crude line to show the phases that iodine will go through.

01:56 Once we change the temperature, it's a constant temperature, but we have a pressure gradient from 0 .01 atmospheres, so it's essentially down here, all the way up to 100 atmospheres.

02:16 So let's get to actually drawing our graph.

02:31 So this is going to be simple.

02:32 We do not need to worry about any specifics.

02:37 We just want to make sure that we get the basic structure of a heating curve down.

02:43 So we have our graph.

02:46 We know that the axes are going to be the same.

02:49 So this is temperature and this is pressure.

02:56 And we write down the range.

02:59 So temperature is at.

03:00 At 185, so that's going to stay the same.

03:06 185 through and through pressure is 0 .01, up to 100.

03:13 So we're essentially going to draw a...