A solid metallic cube of heat capacity S is at temperature 300 K. It i...
Heat taken by cube=S (600-300)=300S
entropy change of reservoir =-300S÷600=-0.5S
entropy change=S ln (600÷300)=0.69S
hence change in entropy universe= 0.69S-0.5S=0.19S
A solid metallic cube of heat capacity S is at temperature 300 K. It i...
Entropy Change of the Reservoir
Given:
Temperature of the cube, T1 = 300 K
Temperature of the reservoir, T2 = 600 K
To find:
Entropy change of the reservoir, ΔSreservoir = ?
Entropy Change Calculation:
The entropy change of a reservoir can be calculated using the equation:
ΔSreservoir = Q/T
where ΔSreservoir is the entropy change of the reservoir, Q is the heat transfer between the reservoir and the cube, and T is the temperature of the reservoir.
Heat Transfer Calculation:
The heat transfer between the reservoir and the cube can be calculated using the equation:
Q = m * c * ΔT
where Q is the heat transfer, m is the mass of the cube, c is the specific heat capacity of the cube, and ΔT is the change in temperature.
Since the cube is solid and metallic, its specific heat capacity is given as S.
ΔT = T2 - T1 = 600 K - 300 K = 300 K
Substituting the values into the equation, we get:
Q = m * S * ΔT
Entropy Change of the Reservoir Calculation:
Now, substituting the value of Q into the entropy change equation, we get:
ΔSreservoir = Q / T2
= (m * S * ΔT) / T2
Since the cube and the reservoir reach thermal equilibrium, their temperatures become equal. Therefore, the final temperature of the cube is also 600 K.
ΔSreservoir = (m * S * ΔT) / T2
= (m * S * ΔT) / T2
= (m * S * 300 K) / 600 K
= (m * S * 0.5)
Since the heat capacity of the cube is given as S, the entropy change of the reservoir is equal to 0.5 times the heat capacity of the cube.
ΔSreservoir = 0.5 * S
Hence, the correct answer is option D) 0.19 S.