Question
Question: In a closed insulated container, a liquid is stirred with a paddle to increase the temperature, whic...
In a closed insulated container, a liquid is stirred with a paddle to increase the temperature, which of the following is true?
A) ΔE=ΔW=0,q=0
B) ΔE=ΔW=0,q=0
C) ΔE=0,W=q=0
D) W=0, ΔE=q=0
Solution
We know the First Law of thermodynamics,
The first law of thermodynamics states that energy can be changed over starting with one structure then onto the next yet it can't be made nor devastated.
The numerical expression is,
ΔE=−q+w
Where,
ΔE is the change in internal energy.
q is the amount of heat exchanged.
w is the work done by the system.
Complete step by step answer:
We all know the numerical expression of first law thermodynamics,
ΔE=q+w
An adiabatic cycle is one in which no warmth is picked up or lost by the framework. The principal law of thermodynamics with q=0 shows that all the change in interior energy is as work done. Therefore, from the first law thermodynamics,
ΔE=q+W
On substituting the value of q we get,
⇒ΔE=0+W
ΔE=W
Therefore the change in internal energy is equal to the amount of work done on the system but it is not equivalent to zero.
So, the correct answer is Option A.
Note: One can determine the internal energy for one mole of carbon monoxide using the first law of thermodynamics.
Example:
Let us assume,
The total heat capacity of the calorimeter C=3kJ(oC)−1
The initial temperature T1=22.113oC
The final temperature T2=22.799oC
The change in temperature is given by,
ΔT=T2−T1
On substituting the known values we get,
⇒ΔT=22.799oC−22.113oC
On simplifying we get,
⇒ΔT=0.686oC
The change in temperature is 0.686∘C
The amount of heat interchange can be estimated as,
q=CΔT
q=3kJ(oC)−1×0.686oC
q=2.058kJ
The heat released=The heat gained by the calorimeter
The quantity of heat get by the calorimeter is −2.058kJ
In bomb calorimeter the volume is fixed therefore the work done by the calorimeter is given by,
w=PΔV
w=0
The work done by the calorimeter is zero.
The internal energy change can be calculated as,
ΔE=q+w
ΔE=−2.058kJ
The internal energy change is −2.058kJ
The internal energy for one mole of carbon monoxide can be calculated as,
ΔE=1.40g−2.058kJ×1mol38g=−41.16kJ/mol
The internal energy for one mole of carbon monoxide is −41.16kJ/mol.