Ideal Gases

Question 1

SI base unit for measurement of amount of substance?

Answer 1

moles

Question 2

avagandro constant

Answer 2

1 mole of any substance contains 6.02x10^23 individual atoms or molecules therefore thee number of atoms or molecules in a substance is equal to number of moles x avagandro constant
N=n*Na

Question 3

kinetic theory of matter

Answer 3

model used to describe the behaviour of the atoms or molecules in an ideal gas

Question 4

what are the assumptions made in the kinetic model for an ideal gas

Answer 4

• the gas contains a very large number of atoms or molecules moving in random directions with random speeds
• the atoms or molecules of the gas occupy a negligible volume compared with the volume of the gas
• the collision of atoms or molecules with each other and the container walls are perfectly elastic (no kinetic energy is lost)
• the time of collisions between the atoms or molecules is negligible compared to the time between the collisions
  electrostatic forces between the atoms or molecules are negligible except during collisions

Question 5

how do the atoms or molecule in an ideal gas cause pressure?

Answer 5

• The atoms in a gas are always moving
• when they collide with the walls of the container, the container exerts a force on them changing their momentum as they bounce off the wall
• when an atom collides with the container wall elastically, its speed doesn’t change but its velocity changes from +u to -u.
• the total change in momentum is -2mu
• the atoms collided with container walls frequently. according to newtons 3rd law, the atom also exerts an equal and opposite force on the wall.
  pressure= force/area

Question 6

whats the relationship between pressure and volume in ideal gases

Answer 6

pressure is inversely proportional to volume when temperature of mass of a gas remain constant

Question 7

boyles law

Answer 7

this is when pressure is inversely proportional to its volume

Question 8

what is the relationship between pressure and temperature

Answer 8

pressure is directly proportional to temperature where p/t= constant only when volume and mass of gas are constant

Question 9

distribution of particle speeds at different temperatures

Answer 9

this range of speeds of particles in a gas at given temperatures is known as the Maxwell-Boltsmann distribution.
Changing the temperature of the gas changes the distribution. The hotter the gas becomes, the greater the range of speeds. the speeds and rms speed increase, the distribution becomes more spread out

Question 10

internal energy of an ideal gas

Answer 10

doubling the temperature will double its internal energy