Calculate the root-mean square speed of the molecules of hydrogen at 20 C ∘ given that each molecule of hydrogen has mass 3 . 35 × 10 - 27 kg .

Given, Temperature = T = 20 o C = 20 + 273 = 293 K Mass of each hydrogen molecule = M = 3 . 35 × 10 - 27 K g For root-mean-square speed of hydrogen molecules V r m s = 3 R T / M = 3 × 8 . 314 × 293 / 3 . 35 × 10 - 27 = 1 . 476 m / s e c

EASY

AS and A Level

IMPORTANT

Earn 100

Four molecules have speeds $200, 400, 600$ and $800 m s^{- 1}$ . Calculate their root-mean-square speed $c_{r.m.s}$ .

Important Questions on Ideal Gases

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>Questions>Q 19

Calculate the root-mean square speed of the molecules of hydrogen at

20 {}^{\circ}C

given that each molecule of hydrogen has mass

3.35 \times 10^{- 27} kg

MEDIUM

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>Questions>Q 20

Show that, if the mean speed of the molecules in an ideal gas is doubled, the thermodynamic temperature of the gas increases by a factor of four.

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>Questions>Q 21

A fixed mass of gas expands to twice its original volume at a constant temperature. How do the pressure of the gas change?

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>Questions>Q 21

A fixed mass of gas expands to twice its original volume at a constant temperature. How do the following change? The mean translational kinetic energy of its molecules.

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>Questions>Q 22

Air consists of molecules of oxygen (molar mass

= 32 g {mol}^{- 1}

) and nitrogen (molar mass

= 28 g {mol}^{- 1}

). Calculate the mean translational
k.e. of these molecules in air at

20 ° C

. Use your answer to calculate the root-mean-square speed of each type of molecule.

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>Questions>Q 23

Show that the change in the internal energy of one mole of an ideal gas per unit change in temperature is always a constant. What is this constant?

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>REFLECTION

Without looking at your textbook, make a list of the kinetic theory equations and write down what each term in the equations means.

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 20 - Ideal Gases>REFLECTION

Write out a proof on your own of the main kinetic theory equation using momentum change and Newton's laws.

Four molecules have speeds 200,400,600 and 800 m s-1. Calculate their root-mean-square speed cr.m.s .

Important Questions on Ideal Gases

Learn and Prepare for any exam you want !

Four molecules have speeds $200, 400, 600$ and $800 m s^{- 1}$ . Calculate their root-mean-square speed $c_{r.m.s}$ .