Question

JEE ADVANCED CHEMISTRY QUESTION SEPTEMBER 2020

Answer 1

if the distribution of molecular speeds of a gas is as per figure shown below, then the ratio of the most probable, the average and the root mean square speed respectively, is

solution : see the graph, it is symmetrical. so the average value of velocities will be at the middle of graph. most probably velocity is also known as symmetrical velocity lying at the middle of graph.

so, the most probable speed = average speed

now to calculate root mean square velocity, we have to find average of square of velocities and then take square root. it must be greater than the average speed of gas.

so, most probable = average < rms speed

this condition only satisfied by option (2).

Therefore the correct answer is option (2)