Expressions Of Pj Problems

Pj Problems - Overview

Celestial Stars

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7 Spaces Of Interest - Overview

Triadic Unit Mesh

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COHN - Natures Engineering Of The Human Body

The Human-Body Systems

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Differential Calculus

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Painting

Molar Entropy Of Water

The molar entropy of ice at 0^{o}C is given as 51.84 J deg^{-1} mole^{-1}.

(a) What is the molar entropy of water at 0^{o}C?

(b) What is the molar entropy of water at 25^{o}C ?

**The strings**:

S_{7}P_{5}A_{51} (Change - Physical Change)
**The math**:

Pj Problem of Interest is of type *change* (physical change). Entropy is a state variable and the problem of interest is a change in entropy (ΔS). Phase changes are physical changes hence the change is physical change.

(a) Heat of fusion during the melting of one mole of ice = 6010 J deg^{-1}

So, system absorbs 6010 J deg^{-1} without change in temperature.

So, entropy increases by 6010/273.15 = 22 J deg^{-1} mole^{-1}

where 273.15 is from the Kelvin temperature scale.

So, molar entropy of water at 0^{o}C = 51.84 + 22 = 73.84 J deg^{-1} mole^{-1}

(b) To obtain the molar entropy of water at 25^{0}, determine increase in entropy due to increase in temperature from 0^{o}C to
25^{o}C (273^{o}K to 298^{o}K)

So increase in entropy = ΔS = ∫_{273}^{298} C_{p}(dT/T).

where T is temperature and C_{p} is heat capacity at constant pressure.

So, ΔS = C_{p}ln(298/273) = 0.0880C_{p}

C_{p} = 75.3 J deg^{-1} mole^{-1} (from commonly available heat capacity /specific heat table).

So, ΔS = 0.0880 x 75.3 = 6.63.

So, molar entropy of water at 25^{o}C = 73.84 + 6.63 = 80.47 J deg^{-1} mole^{-1}

Math

The *point* **.** is a mathematical abstraction. It has negligible size and a great sense of position. Consequently, it is front and center in abstract existential reasoning.

Derivation Of The Area Of A Circle, A Sector Of A Circle And A Circular Ring

Derivation Of The Area Of A Trapezoid, A Rectangle And A Triangle

Derivation Of The Area Of An Ellipse

Derivation Of Volume Of A Cylinder

Derivation Of Volume Of A Sphere

Derivation Of Volume Of A Cone

Derivation Of Volume Of A Torus

Derivation Of Volume Of A Paraboloid

Volume Obtained By Revolving The Curve y = x^{2} About The X Axis

Single Variable Functions

Absolute Value Functions

Conics

Real Numbers

Vector Spaces

Equation Of The Ascent Path Of An Airplane

Calculating Capacity Of A Video Adapter Board Memory

Probability Density Functions

Boolean Algebra - Logic Functions

Ordinary Differential Equations (ODEs)

Infinite Sequences And Series

Introduction To Group Theory

Advanced Calculus - Partial Derivatives

Advanced Calculus - General Charateristics Of Partial Differential Equations

Advanced Calculus - Jacobians

Advanced Calculus - Solving PDEs By The Method Of Separation Of Variables

Advanced Calculus - Fourier Series

Advanced Calculus - Multiple Integrals

Production Schedule That Maximizes Profit Given Constraint Equation

Separation Of Variables As Solution Method For Homogeneous Heat Flow Equation

Newton And Fourier Cooling Laws Applied To Heat Flow Boundary Conditions

Fourier Series

Derivation Of Heat Equation For A One-Dimensional Heat Flow

Homogenizing-Non-Homogeneous-Time-Varying-IBVP-Boundary-Condition

The Universe is composed of *matter* and *radiant energy*. *Matter* is any kind of *mass-energy* that moves with velocities less than the velocity of light. *Radiant energy* is any kind of *mass-energy* that moves with the velocity of light.

Periodic Table

Composition And Structure Of Matter

How Matter Gets Composed

How Matter Gets Composed (2)

Molecular Structure Of Matter

Molecular Shapes: Bond Length, Bond Angle

Molecular Shapes: Valence Shell Electron Pair Repulsion

Molecular Shapes: Orbital Hybridization

Molecular Shapes: Sigma Bonds Pi Bonds

Molecular Shapes: Non ABn Molecules

Molecular Orbital Theory

More Pj Problem Strings