Ch.5 - GasesSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Increasing the temperature allows a gas to absorb thermal energy and convert into kinetic energy. Kinetic energy allows the gas to move and the speed at which it moves gives us the root mean square speed

Root Mean Square Speed & Kinetic Energy

Concept #1: Understanding kinetic energy & Root Mean Square Speed

Example #1: A 1.56 x 1013 pg gaseous particle travels at 6.21 m/s. Determine its kinetic energy. 

The kinetic energy (in J or kJ) of a gas molecule is directly proportional to its absolute temperature in Kelvins. 

Practice: Calculate the molar mass, in g/mol, of a gaseous compound with an average root mean velocity of 652 m/s at a temperature of 30C.

Remember that using the root mean square speed equation deals with molar mass in g/mol, so further conversion may sometimes be needed. 

Additional Problems
A 0.81 mole sample of CO2 is confined in a 20 L container. The volume of the gas sample is decreased to 10L while holding temperature constant. The average molecular speed will. a. increase b. decrease c. remain the same d. insufficient information to answer
What is the root mean square speed (in m/s) of hydrogen molecules at 25.0°C?                   ( R= 8.3145 kg m2 s-2 mol -1 k-1)   a) no given answer is close b) 3.72 x 106 c) 6.10 x 101 d) 1.93 x 103 e) 3.72 x 103  
WF6 is one of the heaviest known gases.How much slower is the root-mean-square speed of WF6 than He at 300 K?
What is the ratio of urms to ump for a sample of O2(g) at 300 K?
You may want to reference (Pages 415 - 419)Section 10.8 while completing this problem.Fill in the blanks for the following statement: The rms speed of the molecules in a sample of H2 gas at 300K will be ____ times larger than the rms speed of O2 molecules at the same temperature, and the ratio large{frac {u_{ m rms} ( m H_2)}{u_{ m rms}( m O_2)}} _____ with increasing temperature.
You may want to reference (Pages 224 - 230) Section 5.8 while completing this problem.Calculate the root mean square velocity of F2,Cl2, and Br2 at 302 K .
How is the root mean square velocity of a gas related to its molar mass?
You may want to reference (Pages 224 - 230) Section 5.8 while completing this problem.Calculate the root mean square velocity of gaseous xenon atoms at 25 oC.
Calculate the rms speed of NF3 molecules at 28 oC.
Calculate the most probable speed of an ozone molecule in the stratosphere, where the temperature is 270 K.
Consider the following drawing. You may want to reference (Pages 398 - 400) Section 10.7 while completing this problem.If curves A and B refer to two different gases, He and O2 at the same temperature, which curve corresponds to He?
Consider the following drawing. You may want to reference (Pages 398 - 400) Section 10.7 while completing this problem.For each curve, which speed is highest: the most probable speed, the root-mean-square speed, or the average speed?
You may want to reference (Page 228) Section 5.8 while completing this problem.Calculate the root mean square velocity of I2(g) at 377 K.
Calculate the rms speed of CO molecules at 315 K .
How does the approximate root mean square velocity of neon compare to that of krypton at the same temperature?
Calculate the rms speed of Cl2 molecules at 315 K .
Calculate the most probable speed of CO molecules at 315 K .
Calculate the most probable speed of Cl2 molecules at 315 K .
You have a sample of gas at -32 oC. You wish to increase the rms speed by a factor of 2.To what temperature should the gas be heated?
Consider the following drawing. You may want to reference (Pages 398 - 400) Section 10.7 while completing this problem.If A and B refer to the same gas at two different temperatures, which represents the higher temperature?
The root mean square speed of nitrogen molecules in air at 20°C is 511 m/s in a certain container. If the gas is allowed to expand to twice its original volume, the root mean square velocity of nitrogen molecules drops to 325 m/s. Calculate the temperature after the gas has expanded.1. 45.1°C2. −45.1°C3. 261°C4. 347◦C5. −347°C6. −261°C7. 154°C8. −154°C
Which gas will have the highest root mean square velocity at the same temperature?NH­­3     b) He     c) CO2      d) SO2      e) NO2
Which of the following gases will have the largest root mean square speed at 100◦C?1. water2. argon3. oxygen4. methane 5. nitrogen
The root-mean-square speed of gas molecules is 256.0 m/s at a given T. The gas has a molar mass of 32.00 g/mol. What would be the root-mean-square speed for a gas with a molar mass of 131.0 g/mol?a. 126.5 m/sb. 62.53 m/sc. 518.0 m/sd. 1048 m/se. 189.8 m/s
Calculate the root mean square velocity of nitrogen molecules at 25.0°C. (1kg = 1000g)A) 729 m/s           B) 515 m/s     C) 149 m/s     D) 16.29 m/s     E) 51.2 m/s
What is the root mean square velocity (m/s) of H2O steam at 373 K?A) 2.26B) 22.7C) 71.4D) 372E) 719 
Identify the gas particle that would travel the fastest at a temperature of 293 K.A. SO2B. CO2C. N2D. NeE. Ar
What is the root mean square speed of carbon dioxide molecules at 98°C? 1. 45.6 m · s -12. 574 m · s -13. 236 m · s -14. 459 m · s -15. 153 m · s -1
Helium is the lightest noble gas in the air. Calculate its root-mean-square speed (in m/s) in the winter when it is 0oC outside. (R = 8.3145 kg m 2 s -2 mol -1 K -1)a. 1845b. 1305c. 1.71 x 103d. 1.70 x 106e. 41.3
Calculate the root mean square velocity of nitrogen molecules at 25 oC
A 1-L sample of CO initially at STP is heated to 546 K, and its volume is increased to 2 L.(c) What is the effect on the root mean square speed of the molecules?
Helium (He) is the lightest noble gas component of air, and xenon (Xe) is the heaviest. [For this problem, use R = 8.314 J/(mol·K) and express ℳ in kg/mol.](a) Find the rms speed of He in winter (0.°C) and in summer (30.°C).
Helium (He) is the lightest noble gas component of air, and xenon (Xe) is the heaviest. [For this problem, use R = 8.314 J/(mol·K) and express ℳ in kg/mol.](b) Compare the rms speed of He with that of Xe at 30.°C.
The root mean square speed of H2 molecules at 25 °C is about 1.6 km/s. What is the root mean square speed of a N2 molecule at 25 °C?
Calculate the root mean square velocities of CH4(g) and N2(g) molecules at 273 K and 546 K.
You may want to reference (Pages 224 - 230) Section 5.8 while completing this problem.Calculate the root-mean-square velocity of CO2 at 286 K .
You may want to reference (Pages 224 - 230) Section 5.8 while completing this problem.Calculate the root-mean-square velocity of CO at 286 K .
The lunar surface reaches 370 K at midday. The atmosphere consists of neon, argon, and helium at a total pressure of only 2×10−14 atm. Calculate the rms speed of each component in the lunar atmosphere. [Use R = 8.314 J/(mol·K) and express ℳ in kg/mol.]
You may want to reference (Pages 224 - 230) Section 5.8 while completing this problem.Calculate the root-mean-square velocity of SO3 at 286 K .
Can the speed of a given molecule in a gas double at constant temperature? Explain your answer.
Of these gases, which has the fastest-moving molecules (on average) at a given temperature?a. HBrb. NO2c. C2H6d. they all have the same average speed
Consider separate 1.0-L samples of He(g) and UF6(g), both at 1.00 atm and containing the same number of moles. What ratio of temperatures for the two samples would produce the same root mean square velocity?
Find the rms speed of the molecules of a sample of N2 (diatomic nitrogen) gas at a temperature of 33.3°C
The average kinetic energy of the molecules in a gas sample depends only on the temperature, T. But given the same kinetic energies, a lighter molecule will move faster than a heavier molecule. rms speed = √3RT/M where R=8.314 J/(mol • K) and M is molar mass in kilograms per mole. Note that a joule is the same as a kg • m2/s2. What is the rms speed of N2 molecules at 287 K?What is the rms speed of He atoms at 287 K?
Calculate the root-mean-square speed of methane, CH4 (g), at 78 °C. (a) 23 m/s (b) 350 m/s(c) 550 m/s (d) 667 m/s (e) 739 m/s