Homework

Jul 8, 2024

Question

Question: A block of copper and one of aluminum each has a mass of 1 kg. Initially, the temperature of the copper block is 150 ° C and the temperature of the aluminum block is 50 ° C. The blocks are isolated from the environment. They put in thermal contact with each other. Find the equilibrium temperature, the total entropy change and determine if the process isA block of copper and one of aluminum each has a mass of 1 kg. Initially, the temperature of the copper block is 150 ° C and the temperature of the aluminum block is 50 ° C. The blocks are isolated from the environment. They put in thermal contact with each other. Find the equilibrium temperature, the total entropy change and determine if the process is reversible, irreversible and impossible. The specific heat of copper is 0.385 kJ / kg Ky and the specific heat of aluminum is 0.9 kJ / kg K.

Answer

Solution :

Given Data :-

Mass of copper and aluminum m = mcu = mA = 1 kg

Initial temperature of copper (Tcu)1 = 150C = 423K

Initial temperature of aluminum (TAI)1 = 50C = 323 K

The specific heat of copper Cou= 0.385 kJ/kg.K

The specific heat of aluminum CAL = 0.9 kJ/kg.K

There is no work or heat transfer with environment, so W = AQ = 0

Applying first law of thermodynamics for this system:

\therefore \Delta Q-W=\Delta U

As, AQ =W=0+ AU = 0

\textup{where, } \Delta U \textup{ is change in internal energies of system.}

\therefore \Delta U_{Cu}+\Delta U_{Al}=0

\therefore [mC(T_2-T_1)]_{Cu}+[mC(T_2-T_1)]_{Al}=0

As we know (Tcu)2 = (TA12 = T2

\therefore [1(0.385)(T_2-150)]+[1(0.9)(T_2-50)]=0

\therefore 1.285\, T_2\, -102.75=0

{\color{DarkBlue} \therefore \, T_2\,=79.9611^{\circ}\, C=352.961\, K}\, \, \, \, \textbf{(\textup{Equillibrium temperature})}

\textup{The entropy change for solid object is given as : }\Delta S=mC\ln \left (\frac{T_2}{T_1} \right )

\textup{Total entropy change of system is given as : }\Delta S=\Delta S_{Cu}+\Delta S_{Al}

\Delta S=\left [mC \ln \left ( \frac{T_2}{T_1} \right ) \right ]_{Cu}+\left [mC \ln \left ( \frac{T_2}{T_1} \right ) \right ]_{Al}

352.9611 AS = 1(0.385) In (4231+ (0.5) 352.9611 323 )

{\color{DarkBlue} \Delta S=0.01014446\, \,\textup{ kJ/K}=10.14446\, \, \textup{ J/K}} \, \, \textbf{(Total entropy change)}

\textup{As the total entropy change is greater than zero. }(\Delta S)>0

\textup{Hence the process is\textbf{ irreversible.}}

Education Tags
:
- Homework help
- Study resources
- Academic assistance
- Le
- arning materials
- Educational support
- Online tutoring
- Study guides
- Exam preparation
- Homework solutions
- School assignments
Subject-specific Tags:
- Mathematics
- Science
- English/Language Arts
- History
- Geography
- Computer Science
- Economics
- Psychology
- Sociology
- Literature
Grade Level Tags:
- Elementary school
- Middle school
- High school
- College
- University
- Graduate level
- K-12
Study Tools Tags:
- Practice problems
- Worksheets
- Flashcards
- Quiz questions
- Lecture notes
- Textbook solutions
- Study tips
- Exam strategies
Online Learning Tags:
- E-learning
- Distance education
- Virtual classroom
- Online courses
- Digital learning
- Remote learning
- Internet resources
Additional Tags:
- Free answers
- Homework assistance
- Academic resources
- Study community
- Student help
- Assignment help
- Problem-solving
- Tutoring services
- Peer collaboration
Chegg Unlock
- Chegg free questions
- Chegg Answers
- Bartleby Answers
- CourseHero unlock
Mail us or contact us if you need any help related to your homework and assignments. Also, for the projects as well.

Related

Related Post

Is this true? Watch Now before it gets deleted

Mar 27, 2026

Homework

Nov 12, 2024

Unable to Restore Whatsapp data from Google Drive?

Jul 10, 2024

Leave a ReplyCancel reply

You missed

Is this true? Watch Now before it gets deleted

March 27, 2026

How to PAMSTAMP Technology

How to save time and monitor simulation in PAMSTAMP?

May 25, 2025

How to PAMSTAMP Technology

Graphical User Interface and File System in PAMSTAMP

May 25, 2025

How to PAMSTAMP Technology

PAMSTAMP Overview and how to start using it?

May 24, 2025