Skip to main content
Ch 18: Thermal Properties of Matter
Young & Freedman Calc - University Physics 15th Edition
Young & Freedman Calc15th EditionUniversity PhysicsISBN: 9780135159552Not the one you use?Change textbook
Chapter 18, Problem 31d

Oxygen (O2) has a molar mass of 32.0 32.0 g/mol. What is the momentum of an oxygen molecule traveling at this speed?

Verified step by step guidance
1
First, understand that momentum (p) is calculated using the formula: p = mv, where m is the mass and v is the velocity of the object.
To find the mass of a single oxygen molecule, use the molar mass of oxygen (32.0 g/mol) and Avogadro's number (6.022 x 10^23 molecules/mol). Convert the molar mass from grams to kilograms by dividing by 1000.
Calculate the mass of one oxygen molecule by dividing the molar mass in kilograms by Avogadro's number: m = (32.0 g/mol) / (6.022 x 10^23 molecules/mol).
Once you have the mass of a single oxygen molecule, use the given velocity to calculate the momentum using the formula: p = mv.
Ensure that all units are consistent, particularly that mass is in kilograms and velocity is in meters per second, to obtain the momentum in kg·m/s.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For oxygen (O2), the molar mass is 32.0 g/mol, which means one mole of oxygen molecules weighs 32 grams. This concept helps in converting between the mass of a substance and the number of molecules or atoms it contains.
Recommended video:
Guided course
20:32
Mass Spectrometers

Momentum

Momentum is a measure of the motion of an object and is calculated as the product of an object's mass and velocity (p = mv). It is a vector quantity, meaning it has both magnitude and direction. Understanding momentum is crucial for determining how the motion of an object, like an oxygen molecule, changes when it interacts with other objects or forces.
Recommended video:
Guided course
05:17
Intro to Momentum

Molecular Speed

Molecular speed refers to the velocity at which a molecule travels. In the context of gases, molecules move at various speeds depending on temperature and mass. The speed of an oxygen molecule is essential for calculating its momentum, as momentum depends directly on both the mass and velocity of the molecule.
Recommended video:
Guided course
01:50
Introduction to Kinetic-Molecular Theory
Related Practice
Textbook Question

A flask contains a mixture of neon (Ne), krypton (Kr), and radon (Rn) gases. Compare the root-mean-square speeds. (Hint: Appendix D shows the molar mass (in g/mol) of each element under the chemical symbol for that element.)

20
views
Textbook Question

Oxygen (O2) has a molar mass of 32.0 32.0 g/mol. What is the average translational kinetic energy of an oxygen molecule at a temperature of 300300 K?

Textbook Question

Oxygen (O2) has a molar mass of 32.0 32.0 g/mol. Suppose an oxygen molecule traveling at this speed bounces back and forth between opposite sides of a cubical vessel 0.100.10 m on a side. What is the average force the molecule exerts on one of the walls of the container? (Assume that the molecule's velocity is perpendicular to the two sides that it strikes.)

1
views
Textbook Question

Oxygen (O2) has a molar mass of 32.032.0 g/mol. How many oxygen molecules traveling at this speed are necessary to produce an average pressure of 11 atm?

1
views
Textbook Question

Calculate the mean free path of air molecules at 3.50×10133.50\(\times\)10^{-13} atm and 300300 K. (This pressure is readily attainable in the laboratory; see Exercise 18.2318.23.) As in Example 18.818.8, model the air molecules as spheres of radius 2.0×10102.0\(\times\)10^{-10} m.

1
views
Textbook Question

The atmosphere of Mars is mostly CO2 (molar mass 44.044.0 g/mol) under a pressure of 650650 Pa, which we shall assume remains constant. In many places the temperature varies from 0.00.0°C in summer to 100-100°C in winter. Over the course of a Martian year, what are the ranges of the rms speeds of the CO2 molecules.

1
views