Molecular Physics | Thermodynamics Answers

A drink is cooled more by ice at0°C than by the same mass of water at 0°C this is because ice is

we know that entropy is a point function i.e. it is independent on path followed by the system. Let system changes its state from 1 to 2 by a reversible path, then system returns to its original state by following process 2 to 1. If process 2 to 1 is a reversible process then we can write
[1-2]∫(δQ/T)+[2-1]∫(δQ/T)=0
and if process 2 to 1 is irreversible then we can write
[1-2]∫(δQ/T)+[2-1]∫(δQ/T)<0
entropy is a point function it is not dependent on path followed, but when we changed process 2 to 1 from reversible to irreversible then equation changed, how it is possible?
Note: "[1-2]∫" indicates integration from limit 1 to 2.

The transfer of heat through radiation is achieved by

Option A. the application of radioactive isotopes.
Option B. warming up the intervening medium.
Option C. not warming up the intervening medium.

In 'standard conditions' what is the standard for measurement of volume and density of a liquid or solid?.
Option A. 20 °C and 760mm of Mercury.
Option B. 0 °C and 760mm of Mercury.
Option C. 20 °C and 700mm of Mercury.

In 'standard conditions' what is the standard for measurement of volume and density of a gas?.
Option A. 0 °C and 760mm of Mercury.
Option B. 20 °C and 700mm of Mercury.
Option C. 20 °C and 760mm of Mercury.

The standard temperature and pressure for measuring the density of liquids is.
Option A. 15 °C and 760 mmHg.
Option B. 0 °C and 760 mmHg.
Option C. 4 °C and 760 mmHg.

Calculate the length of a brass rod which shows the same expansion as an iron rod of length 4m, when both rods are heated through the same range of temperature.
Coefficient of linear expansion of brass is 0.000018 per K and iron is 0.000012 per K.

2- The air in the refrigerator is cooled throughout even though the cooling element is at the top of the refrigerator______

As a block of ice is melted (to 4 °C). Its volume.
Option A. remains the same.
Option B. decreases.
Option C. increases.


Which one is true