HW10_ Chap 17.5,17.7, Chap. 18.4-18

HW10: Chap 17.5,17.7, Chap. 18.4-18.6 Due: 11:59pm on Thursday, April 16, 2015 You will receive no credit for items you complete after the assignment is due. Grading Policy

Heat versus Temperature The specific heat capacity of aluminum is about twice that of iron. Consider two blocks of equal mass, one made of  aluminum and the other one made of iron, initially in thermal equilibrium.

Part A Heat is added to each block Heat block at the same constant constant rate until until it reaches reaches a temperatur temperature e of 500 500 following statements is true?

. Which of the

Hint 1. How to approach the problem Heat is added to both blocks at the same constant rate. That is, the same amount of heat is added to each block per unit time. Therefore, the block that reaches the final temperature in the smallest amount of time is the block that requires the smallest amount of heat to undergo the given temperature change. Since both blocks have the same mass and undergo the same temperature change, you can relate the amount of heat absorbed by each block to the block's specific heat capacity.

Hint 2. Specific heat capacity Given a sample of mass of a certain substance, the amoun amountt of heat by an amoun amountt is given by

needed need ed to change its temperatur temperature e

, where is the specific heat capacity where capacity characteristic of that substance. substance. It follows follows that the specific heat capacity capaci ty of a sample is the amount of heat required to raise the temperature of of one gram of the sample by 1 .

Hint 3. Identify which material requires more heat Consider several one-gram samples of different materials. Heat is added to each sample to increase its temperature by 1 . Which material will absorb the most heat?

Hint 1. Definition of specific heat capacity The specific specific heat capacity capacity of a sample is the amount amount of heat heat required required to raise raise the temperatur temperature e of  one gram of that sample by 1 .

 ANSWER: The material with the smallest specific heat capacity will absorb the most heat. The material with the largest specific heat capacity will absorb the most heat.  All the materials will absor absorb b the same amoun amountt of heat because they all have the same mass.  All the materials will absor absorb b the same amoun amountt of heat because they all unde undergo rgo the same change in temperature.

 ANSWER: The iron takes less time than the aluminum to reach the final temperature. The aluminum takes less time than the iron to reach the final temperature. The two blocks take the same amount of time to reach the final temperature.

Correct

Part B When the two materials have reached thermal equilibrium, the block of aluminum is cut in half and equal quantities of heat are added to the iron block and to each portion of the aluminum block. Which of the following statements is true?

Hint 1. How to approach the problem Since the same quantities of heat are added to samples that have different masses and different specific heat capacities, this may result in different final temperatures for each sample. However, you must keep in mind that each smaller block of aluminum now has half the mass of the iron block, but about twice the specific heat capacity. To solv solve e this problem use propor proportional tional reasoning to find a relation between , , and . Find the simplest equation that contains these variables and other known quantities from the problem. Write this equation twic twice: e: once to describe , , and and again to relate , , and , where the subsc subscript ript i refers to iron and a to aluminum. Write each equation so that all the constants are on one side and the variables are on the other.. In this prob other problem lem the variable is so wr write ite your equa equations tions in the form . Finally, compare the two cases presented in the problem. For this question you should find the ratio .

Hint 2. Find the temperature change of the iron block When an amount of heat is absorbed by the block of iron, what is its change in temperature and for the mass of the iron block and and the specific heat capacity of iron, respectively. Express your answer in terms of

,

, and

? Use

.

Hint 1. Specific heat capacity Given a mass an amount

of a certain subst substance, ance, the amount of heat is given by

needed to change its temperature by

, where whe re

 ANSWER:

is a constant, called specific heat capacity, characteristic of that substance. substance.

=

Hint 3. Find the temperature change of the smaller aluminum block When an amount of heat is absorbed by the block of iron, what is its change in temperature ? Express the mass of the block in terms of the mass of the iron block and the specific heat capacity of  aluminum in terms of the specific heat capacity of iron . Express your answer in terms of

,

, and

.

Hint 1. Specific heat capacity of aluminum Recall that the specific heat capacity of aluminum is about twice the specific heat capacity of iron.

 ANSWER:

=

 ANSWER: The three blocks are no longer in thermal equilibrium; the iron block is warmer. The three blocks are no longer in thermal equilibrium; both the aluminum blocks are warmer. The blocks remain in thermal equilibrium.

Correct

Understanding Heat Conduction Learning Goal: To understand the heat conduction formula and the variables in it. Conduction--the flow of heat from a hotter object to a cooler object or from a hotter region to a cooler region of the same object--is the most common mechanism of heat transfer. The formula governing this is .

Part A This formula applies to ________________.  ANSWER:

any object of cross-sectional area

; length

; and thermal conductivity

any object of cross-sectional area

; length

; and thermal resistivity

a plate of surface area

; long dimension

; and thermal conductivity

a plate of surface area

; long dimension

; and thermal resistivity

Correct This formula gives the heat conducted at steady state  by any object of uniform heat conductivity and crosssectional area, whose hot and cooler ends are at and , respectively. Typical examples are a wire, rod, or an insulating layer, the latter of which will typically have a large area and relatively short length (thickness) .

Imagine that you are applying the heat conduction formula to a rod that is held at a high temperature on one end and at a low temperature on the other end. Indicate whether the following statements are true or false.

Part B The quantity

is the rate of heat transfer from the hot to the cold end of the rod.

 ANSWER: true false

Correct

Part C The quantity

is the rate of heat added to the hot end of the rod to maintain its temperature.

 ANSWER: true false

Correct

Part D The quantity  ANSWER:

is the rate of heat removed from the cold end of the rod to maintain its temperature.

true false

Correct

Part E The quantity

is the total amount of heat transferred from the hot to the cold end of the rod.

 ANSWER: true false

Correct The flow of heat into, through, and out of the rod are equal under steady state conditions in which the temperature of each end of the rod is constant. The heat conduction formula applies only in steady state; it does not apply to the situation in which one end of a bar is suddenly placed in a flame while the other end is held at fixed temperature (as in an ice bath); the formula would only apply after the temperature at every point in the bar had reached a steady-state value.

Part F In the SI system of units, what are the units of the quantity

?

 ANSWER:  joules amperes watts

Correct

± Heat Flowing through a Sectioned Rod  A long rod, insulated t o prevent heat loss along its sides, is in perfect thermal contact with boiling water (at atmospheric pressure) at one end and with an ice-water mixture at the other . The rod consists of a 1.00 section of copper (with one end in the boiling water) joined end-to-end to a length of steel (with one end in the ice water). Both sections of  the rod have cross-sectional areas of 4.00 . The temperature of the copper-steel junction is 65.0 after a steady state has been reached. Assume that the thermal conductivities of copper and steel are given by and

.

Part A How much heat per second

(

) flows from the boiling water to the ice-water mixture?

Express your answer in watts.

Hint 1. How to approach the problem Because the length of the steel section of the rod is unknown, the equation for the heat conduction cannot be set up directly between the boiling water and the ice water. Instead, since the junction temperature is known, calculate the heat flowing through the copper section only . Because a steady state has been reached, the heat flowing out of the boiling water must be equal to the heat flowing through the copper  section, which is equal to the heat flowing through the steel section, which is finally equal to the heat flowing into the ice water.

Hint 2. Equation for heat conduction The heat current through a rod is , where and are, respectively, the length and cross-sectional area of the rod in contact with each side and is the thermal conductivity of the rod, which depends on the material used to make the rod.

 ANSWER: = 5.39

Correct Because the system is assumed to have reached a steady state, the heat flowing out of the boiling water  must be equal to the heat flowing through the copper section of the rod.

Part B

What is the length

of the steel section?

Express your answer in meters.

Hint 1. How to approach the problem In Part A, you found the heat current through the copper rod, which is the same as the heat current through the steel rod. You also know the temperatures of both ends of the steel rod. Use these values in the heatcurrent equation to calculate the length of the steel rod.

 ANSWER: = 0.242

Correct Extending the analysis from the first part, we see that, since a steady state has been reached, the heat flowing through the copper section must be equal to the heat flowing through the steel section, which is also equal to the heat flowing into the ice water.

± Understanding Heat Radiation Learning Goal: To understand the formula for power radiated in the form of electromagnetic energy by an object at nonzero temperature. Every object at absolute (Kelvin) temperature will radiate electromagnetic waves. This radiation is typically in the infrared for objects at room temperature, with some visible light emitted for objects heated above 1000 . The formula governing the rate of energy radiation from a surface is given by , where

is the thermal power (also known as the heat current

).

Part A This formula applies to _______________.  ANSWER: any object of total surface area

, Kelvin temperature

any object of cross-sectional area any object of total surface area

, Kelvin temperature

, Kelvin temperature

any object of cross-sectional area

, and emissivity , and emissivity

, and emissivity

, Kelvin temperature

, and emissivity

Correct In the formula given, is the thermal emissivity. The emissivity is 1.0 for a truly black object and varies down to about 0.02 for a shiny gold-plated object. The Stefan-Boltzmann constant is

and is a constant of nature. Its prediction from first principles was the first major triumph of quantum mechanics, giving

where is Boltzmann's constant, is the speed of light.

is Planck's quantum of angular momentum (or Planck's constant), and

Part B If you wanted to find the area of the hot filament in a light bulb, you would have to know the temperature (determinable from the color of the light), the power input, the Stefan-Boltzmann constant, and what property of the filament?  ANSWER: thermal radiation emissivity length

Correct

Part C If you calculate the thermal power radiated by typical objects at room temperature, you will find surprisingly large values, several kilowatts typic ally. For example, a square box that is 1 on each side and painted black (therefore justify ing an emissivity near unity) emits 2.5 at a temperature of 20 . In reality the net thermal power emitted by such a box must be much smaller than this, or else the box would cool off quite quickly. Which of the following alternatives seems to explain this conundrum best?  ANSWER: The box is black only in the visible spectrum; in the infrared (where it radiates) it is quite shiny and radiates little power. The surrounding room is near the temperature of the box and radiates about 2.5 into the box. Both of the first two factors contribute significantly. Neither of the first two factors is the explanation.

of thermal energy

Correct

Part D  As a rough approximation, the human body may be c onsidered to be a cylinder of length and circumference . (To simplify things, ignore the circular top and bottom of the cylinder, and just consider  the cylindrical sides.) If the emissivity of skin is taken to be , and the surface temperature is taken to be , how much thermal power does the human body radiate? Express the power radiated numerically; give your answer to the nearest 10

.

Hint 1. Find the area of the person Find the area

of the person.

Express the area in terms of

,

, and any constants.

 ANSWER: =

Hint 2. Find a symbolic expression for the power  Find the total power

radiated by the person.

Express your answer in terms of the Stefan-Boltzmann constant , the body area temperature , and the emissivity .

, the body

 ANSWER: =

 ANSWER: = 460

Correct

Exercise 17.26 In an effort to stay awake for an all-night study session, a student makes a cup of coffee by first placing a 200-W electric immersion heater in 0.300 of water.

Part A How much heat must be added to the water to raise its temperature from 21.5

to 86.0

?

 ANSWER: = 8.11×104

Correct

Part B How much time is required? Assume that all of the heater's power goes into heating the water.  ANSWER: = 405

Correct

Degrees of Freedom Thermodynamics deals with the macroscopic properties of materials. Scientists can make quantitative predictions about these macroscopic properties by thinking on a microscopic scale. Kinetic theory and statistical mechanics provide a way to relate molecular models to thermodynamics. Predicting the heat capacities of gases at a constant volume from the number of degrees of freedom of a gas molecule is one example of the predictive power of molecular  models. The molar specific heat of a gas at a constant volume is the quantity of energy required to raise the temperature of one mole of gas by one degree while the volume remains the same. Mathematically, , where

is the number of moles of gas,

is the change in internal energy, and

is the change in temperature.

Kinetic theory tells us that the temperature of a gas is directly proportional to the total kinetic energy of the molecules in the gas. The equipartition theorem says that each degree of freedom of a molecule has an average energy equal to , where , where

is Boltzmann's constant

. When summed over the entire gas, this gives

is the ideal gas constant, for each molecular degree of freedom.

Part A Using the equipartition theorem, determine the molar specific heat, degrees of freedom. Express your answer in terms of

, of a gas in which each molecule has

and .

Hint 1. How to approach the problem The molar specific heat of a substance is the amount of energy required to increase the temperature of one mole of the substance by one degree Celsius. Using the equipartition theorem, determine by how much the total energy of a gas increases when its temperature increases by one degree. Then apply the formula given

in the problem introduction for

.

Recall that a change in temperature reflects a change in the amount of energy associated with each  degree of freedom.

Hint 2. Monatomic gas: an example The molar specific heat for a monatomic gas is

.

 A monatomic gas has three degrees of freedom, one for each of the three Cartesian directions. By the equipartition theorem, when the temperature of the gas changes, the energy in each degree of freedom changes by an amount

.

 ANSWER: =

Correct Experimentally, kinetic theory and the equipartition theorem do a good job of predicting the specific heat of  many gases at room temperature as shown in the chart below. Molecule

Degrees of Freedom

 Argon (Ar)

12.5

1.50

3

Helium (He)

12.5

1.50

3

Carbon Monoxide (CO)

20.7

2.49

5

Hydrogen (H2)

20.4

2.45

5

Nitric Oxide (NO)

20.9

2.51

5

Hydrogen Sulfide (H2S)

25.92

3.12

6

Water Vapor (H2O)

25.24

3.03

6

For a monatomic gas, there are only three translational degrees of freedom, so

is about

. Diatomic

molecules and linear molecules have three translational degrees of freedom and two rotational components to the motion (rotation about the axis of the molecule does not contribute much except at high temperatures), giving

a value of about

freedom, which gives

. Nonlinear molecules have three translational and three rotational degrees of  .

Polyatomic molecules also have vibrational degrees of freedom, where the bonds between atoms can vibrate back and forth like a spring being compressed and released as well as possible side-to-side swinging motion from the bonds bending. The vibrational motion does not normally contribute to the degrees of freedom until a high temperature of 400 degrees Celsius or more is reached.

Part B Given the molar specific heat of a gas at constant volume, you can determine the number of degrees of  freedom that are energetically accessible.

For example, at room temperature cis-2-butene,

, has molar specific heat

. How many

degrees of freedom of cis-2-butene are energetically accessible? Express your answer numerically to the nearest integer.

Hint 1. How to approach the problem In Part A, you derived an equation for in terms of the number of degrees of freedom . Substitute known quantities into that equation and solve for .

 ANSWER: = 17

Correct

± The Speed of Nitrogen Molecules The kinetic theory of gases states that the kinetic energy of a gas is directly proportional to the temperature of the gas.  A relationship between the mic roscopic properties of the gas molecules and the macroscopic properties of the gas can be derived using the following assumptions: The gas is composed of pointlike particles separated by comparatively large distances. The gas molecules are in continual random motion with collisions being perfectly elastic. The gas molecules exert no long-range forces on each other. One of the most important microscopic properties of gas molecules is velocity. There are several different ways to describe statistically the average velocity of a molecule in a gas. The most obvious measure is the average velocity . However, since the molecules in a gas are moving in random directions, the average velocity is approximately zero. Another measure of velocity is , the average squared velocity . Since the square of velocity is always positive, this measure does not average to zero over the entire gas. A third measure is the root-mean-square (rms) speed, , equal to the square root of . The rms speed is a good approximation of the the typical speed of  the molecules in a gas. This histogram shows a theoretical distribution of speeds of molecules in a sample of nitrogen ( problem, you'll use the histogram to compute properties of the gas.

) gas. In this

Part A What is the average speed

of the molecules in the gas?

Express your answer numerically to three significant digits.

Hint 1. How to use the histogram The histogram shows the fraction of molecules that have speeds within each of a set of ranges. Each speed range is called a bin. Take the central speed value of each bin as an estimate of the speed of all the molecules in that bin. Compute the weighted average speed, using the percentage of molecules in a bin as the weighting factor for that bin.

Hint 2. More on computing the average To find the weighted average, take the average speed of the molecules in each "bin" (for example, the average speed of molecules in the 0-200 range is 100), and multiply that value by the fraction of molecules in that bin. Repeat this process for each bin, adding the results. This will give you the average speed of the molecules in the gas.

 ANSWER: = 474

Correct

Part B Because the kinetic energy of a single molecule is related to its velocity squared, the best measure of the kinetic energy of the entire gas is obtained by computing the mean squared velocity, , or its square root . The quantity

is more common than

velocity-squared.

because it has the dimensions of velocity instead of the less-familiar 

What is the rms speed

of the molecules in the nitrogen gas?

Express your answer numerically to three significant digits.

Hint 1. How to approach the problem The rms speed of a system of molecules is the square root of the average of the squares of the velocities. Take the central speed value of each bin as an estimate of the speed of all the molecules in that bin. Compute the weighted average squared speed, using the percentage of molecules in a bin as the weighting factor for that bin. Then take the square root.

Hint 2. Find the mean square velocity What is the mean square velocity

for the given distribution of molecules?

Express your answer numerically in meters squared per second squared to three significant figures.

Hint 1. Understanding mean square velocity The mean square velocity is given by

, where the sum is taken over all the

molecules in the gas and is the total number of molecules. If you take the central speed value of  each bin as an estimate of the speed of all the molecules in that bin, this equation reduces to , where the sum is now over the number of discrete bins and equivalently the percentage of molecules) in a particular bin.

is the number of molecules (or 

 ANSWER: = 2.69×105

 ANSWER: = 519

Correct  A speed of 519 is comparable to that of a bullet shot from a handgun. In contrast, a Boeing 747 jet airliner has a maximum air speed of 270 and the speed of sound in air is only about 330 . The speed of sound in air must be slower than the average speed of the molecules because it is the movement of the molecules that transmits sound.

Part C What is the temperature

of the sample of

gas described in the histogram?

Express your answer in degrees Celsius to three significant figues.

Hint 1. How to approach the problem Using the assumptions of kinematics, the ideal gas law, and the formula for kinetic energy, it can be shown that , where is the ideal gas constant, is the temperature in kelvins, and is the molar mass in kilograms. Solve this equation for

. Use

.

Hint 2. Find the molar mass of N2 To three significant figures, the weight of nitrogen is 14.0 molecule?

. What is the molar mass

of the

Express your answer in grams per mole to three significant figures.  ANSWER: = 28.0

 ANSWER: = 29.4

Correct

Part D The histogram used in this problem is obviously only an approximation of the true distribution of velocities in a gas. In reality, the molecules span a continuous range of velocities. For a given temperature, the majority of the molecules have a speed near the average speed, with a few molecules traveling very fast or very slow. To good approximation, the speeds of molecules in a gas follow what is known as the Maxwell-Boltzmann distribution. This applet allows you to see the curves for the Maxwell-Boltzmann distribution at many different temperatures. It also lets you move a small interval around on the histogram to highlight all of the molecules within the speed range of  that part of the histogram. Which of the following describes the qualitative behavior of the Maxwell-Boltzmann distribution as temperature increases? You will have to press the "reset" button on the applet before you can change the temperature using the thermometer on the right side.  ANSWER: The peak moves to the right, while the distribution becomes more spread out. The peak moves to the right, while the distribution becomes less spread out. The peak moves to the left, while the distribution becomes more spread out. The peak moves to the left, while the distribution becomes less spread out.

Correct  At the higher temperatures, the peak of the curve shifts to the right, indicating a higher average velocity . The peaks of the higher temperature curves are also broader, indicating that a greater percentage of molecules are traveling at a higher velocity than in the low-temperature case.

Exercise 18.41

Part A How much heat does it take to increase the temperature of 3.50 moles of a diatomic ideal gas by an amount 40.0  if the gas is held at constant volume? The gas molecules can translate and rotate but not vibrate. Express your answer using three significant figures.  ANSWER: = 2910

Correct

Part B What is the answer to the question in part (A) if the gas is monatomic? Express your answer using three significant figures.  ANSWER: = 1750

Correct

Storing Ammonia  Ammonia ( ) is a colorless, pungent gas at standard pressure and temperature. It is a natural metabolic byproduct, usually getting released in respiration, sweat, and urine. However, because ammonia is caustic, exposure to large quantities of it can cause illness and even death. Despite its inherent dangers, ammonia is environmentally friendly in small quantities and has many applications in our economy. It can be used as a fertilizer, as a source of hydrogen gas for welding, as a refrigerant, in the production of nitric acid and sodium carbonate, in metallugy, and in the infamous smelling salts used to revive unconscious people. Ammonia today can be mass produced inexpensively in chemical refineries. To safely produce and store ammonia, its physical and thermodynamic properties must be understood. Physically, ammonia is a strong base that reacts with acids and metals. The thermodynamic properties describing the phases of  ammonia (solid, liquid, and gas) and the transitions between the phases are just as important. The relationship of these

phases to pressure and temperature is quantitatively described by ammonia's  pT   phase diagram. Note that, in this diagram, the pressure axis is not to scale. From the diagram, the melting temperature, boiling temperature, and other quantities can be determined for any pressure. The pressure and temperature range for each of the phases is shown by its own unique area of the graph. The lines bounding each of the phases on the diagram represent the temperatures and pressures at which two states can coexist. For this problem, any section of curve on the diagram can be named using two letters on the boundary in alphabetical order. Other points not lying on the boundary can also be used to help identify various thermodynamic processes.

Part A On the phase diagram, which section of curve represents the pressure and temperature values at which ammonia will boil? Express your answer as two letters that lie on a section of the appropriate curve.

Hint 1. Describe boiling in terms of phase changes Boiling is the transition from one phase to another with both phases existing together. The phases and direction of change involved in boiling are __________ to __________. Express your answer as two words separated by commas in the order they appear in the sentence. Choose from the following list: gas, liquid, or solid.  ANSWER: liquid,gas

 ANSWER: boiling curve = CE

Correct

Part B The line between which two points would describe a process of liquid ammonia boiling completely away? Express the answer as two letters representing the endpoints of the line in order so that going from the first letter to the second letter would show a process of boiling. Be careful to put the letters in the correct order.  ANSWER:

HG

Correct

Part C On the phase diagram, which section of curve represents the pressure and temperature values at which ammonia will sublimate? Express the answer as two letters that lie on a section of the appropriate curve.

Hint 1. Describe the process of sublimation The phases and direction of change for sublimation are __________ to __________. Express your answer as two words separated by a comma in the order they appear in the sentence. Choose from the following list: gas, liquid, or solid.  ANSWER: solid,gas

 ANSWER: sublimation curve = BC

Correct

Part D The line between which two points would describe a process of sublimation for ammonia? Express your answer with two letters ordered in the direction of sublimation. Be careful to put the letters in the correct order.  ANSWER:  AF

Correct The heat added to a substance undergoing sublimation must be equal to the heat of fusion plus the heat of  vaporization.

Part E On the phase diagram, which section of curve represents the pressure and temperature values at which ammonia

will melt? Express the answer as two letters that lie on a section of the appropriate curve.  ANSWER: melting curve = CD

Correct

Part F The line between which two points would describe the process of complete melting of ammonia? Express your answer as two letters ordered in the direction of melting. Be careful to put the letters in the correct order.  ANSWER:  AH

Correct

Part G One of the most important points on a phase diagram is the triple point, where gas, liquid, and solid phases all can exist at once. What are the coordinates ( , ) of the triple point of ammonia in the diagram? Express your answer as an ordered pair. Determine the temperature to the nearest 5 one significant digit.

and the pressure to

Hint 1. Determine the letter name for the triple point Given that the triple point is the pressure and temperature at which all three phases can coexist, what is the letter name for the triple point of ammonia? Express the answer as a single letter.  ANSWER: triple point = C

 ANSWER: ,

=

195,0.05

Correct Temperature scales were originally based upon the melting and boiling points of a substance, but these values vary with pressure as seen in the phase diagram of ammonia. So if one did not control and measure the pressure precisely, the measurement used to calibrate the temperature scale would be inaccurate. To circumvent this problem, modern temperature scales are based on the triple point of water. The triple point temperature of water is 0.01 at 0.006 . The three phases of water will not coexist at any other  temperature, regardless of the pressure, so the temperature can be calibrated without an additional pressure measurement. The triple points of mercury and other substances are also used as standards for calibrating thermometers.

Part H  At one atmosphere of pressure and temperatures above , ammonia exists as a gas. For transportation, ammonia is stored as a liquid under its own vapor pressure. This means that the liquid and gas phases exist simultaneously. If a container of ammonia is transported in an temperature-controlled truck that is maintained at no greater than 330 , what maximum pressure must the sides of the container be able to withstand? Express the answer numerically in atmospheres to one significant figure.

Hint 1. How to approach the problem Because the liquid and vapor forms both exist in the container, find the point on the graph where the given temperature intersects the curve representing the phase change of liquid to gas.

 ANSWER: = 8

Correct

Exercise 18.49 Solid water (ice) is slowly warmed from a very low temperature.

Part A What minimum external pressure  ANSWER: = 610

Correct

must be applied to the solid if a melting phase transition is to be observed?

Part B  Above a certain maximum pressure

, no boiling transition is observed. What is this pressure?

 ANSWER: = 2.21×107

Correct Score Summary: Your score on this assignment is 102%. You received 50.8 out of a possible total of 50 points.