Problem 37CQ

Explain why a building made of bricks has smaller entropy than the same bricks in a disorganized pile. Do this by considering the number of ways that each could be formed (the number of microstates in each macrostate).

Solution 37CQ

Step 1 of 2

If a building made of bricks is considered, the bricks are arranged in such a fashion that they are stable upon one another, or in other terms, such a form is much more rigid.

However, if a pile of bricks is considered, each brick can be oriented in any direction and hence the number of microstates for a given macrostate is much higher for the bricks in the pile of bricks compared to the ones in the brick wall.

The more such states available to the system with appreciable probability, the greater the entropy. That is, the greater the number of microstates available to the system, among which energy can be shared, the greater the entropy

Fundamentally, the number of microstates is a measure of the potential disorder of the system, and hence the bricks in a pile have got a larger number of microstates for a given macrostate, the bricks in the pile will have greater entropy.