+91-8076753736[email protected]
logo
logo
-->

Thermodynamics

Question
CBSEENCH11006271
Wired Faculty App

For the reaction at 298 K
                  2 straight A plus straight B rightwards arrow straight C
increment straight H space equals space 400 space kJ space mol to the power of negative 1 end exponent space and space increment straight S space equals space 0.2 space kJ space straight K to the power of negative 1 end exponent mol to the power of negative 1 end exponent.

At what temperature will the reaction become spontaneous considering increment straight H space and space increment straight S to be constant over the temperature range?

Solution

According to Gibb's Helmholtz equation,
                     space increment straight G space minus space increment straight H space minus space straight T increment straight S
At equilibrium,
                increment straight G space equals space 0 space space space space space 0 space equals space increment straight H space minus space straight T increment straight S or space space space straight T space equals space fraction numerator increment straight H over denominator increment straight S end fraction space space space space space space space space space space space space space... left parenthesis 1 right parenthesis
 Here space space increment straight H space equals space 400 space kJ space mol to the power of negative 1 end exponent space space space space space space space space space space increment straight S space equals space 0.2 space kJ space straight K to the power of negative 1 end exponent space mol to the power of negative 1 end exponent
Substituting the values in equation (1), we get
          straight T space equals space fraction numerator 400 space kJ space mol to the power of negative 1 end exponent over denominator 0.2 space kJ space straight K to the power of negative 1 end exponent mol to the power of negative 1 end exponent end fraction space equals space 2000 space straight K
Above this temperature, ∆G will be negative and reaction becomes spontaneous.
                                        

Some More Questions From Thermodynamics Chapter

What do you understand by the terms: the system and surroundings?

Classify the following into different types of systems:
(i) Tea placed in a cup
(ii) Tea placed in a tea-pot
(iii) Tea placed in a thermosflask. 

Define a closed system.

Define an isolated system.

Define intensive properties.

Define extensive properties.

Why all living systems need to be 'open systems'?

Define state variables of a system.

From thermodynamic point of view, to which system the animals and plants belong?

What is a state function?

Mock Test Series

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation