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What is the entropy change when 275 g of water is heated from 20.0°C to 80.0 °cz О 214 J/K O 1600 JK 196 J/K O 236 J/K What is the change in entropy when 175.0 g of steam condenses at the boiling point of water? A. O -943.3 JAK B. 0 -1058 J/KC. -252.8 JK D. 0 -3948 J/K

User Gjohn
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1 Answer

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Answer:

1- 214 J/K

2- -1058 J/K (roughly)

Step-by-step explanation:

1-Given:

mass of water
m=275 g

initial temperature
t_1=20 C=293K

final temperature
t_2=80C=353K

Specific heat capacity of water
C=4.18(J)/(g* K)

1-We can first calculate the change in entropy through the formula:


dS=m* C* ln ((t_1)/(t_2) )


dS=275* 4.18* ln((353)/(293))\\ =214 J/K

2-Given:

mass of water
m=0.175 kg

latent heat of vaporization
L=2.26* 10^6J/kg

(In the case of condensation, we use a negative sign because the heat is expelled out of the system not inside of it)

heat emitted from the condensation of steam:


Q=mL\\\\=0.175 * -2.26* 10^6\\=-3.955* 10^5 J\\\\dS=Q/T\\\\\\=(-3.955* 10^5)/(373)\\ \\=-1060J/K=-1058 J/K (roughly)

User Jim Wooley
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