Reflection | JuE :'D's Profile

The next chapter is second law of thermodynamics. In this chapter i learn about heat engine,heat pum and refrigerator. Before this i don't know how refrigerator in my house work,now i know!! In addition, i also laern about Carnot cycle which is the best and perfect cycle as it is reversible cycle. However, this cycle only used as reference to know is it the system is possible or impossible. I also learn about entropy. Entropy generation increases in irreversible processes. If the entropy generation almost zero, thats mean the cycle is almost perfect.

The last topic is the power and refrigeration cycle. In this chapter i learn about Rankine cycle. Rankine cycle is the modification of the carnot cycle.

Balances on Reactive Processes

In this chapter, enthalpy change to be determined is associated with chemical processes and chemical equation.  Therefore, I have to know on balancing chemical equation in order to learn this chapter.hehe..

Heats of reaction consist of endothermic and exothermic. Endothermic means that the system absorbs heat while exothermic means the system release heat to the surrounding. Since this chapter involving the chemical equation, so the enthalpy change will be doubled if the coefficient of chemical equation is doubled. There are three ways to calculate the heats of reaction.

Ways to calculate the heats of reaction.

#Hess’s Law

#Heat of Formation

#Heat of Combustion

There are two ways to calculate the energy,Q.

#using heat of reaction

-reference states are choosing from the molecules in the chemical equation

Formula: Q = (Extent of reaction) Hr. +(n∑ H out – n ∑ H in)

#using heat of formation

-reference states are the elements of chemical substances involved in the reaction

Formula: (n ∑ H out –n ∑ H in)

Assalamualaikum and Salam 1 Malaysia…

First and foremost, I would like to express my thanks to Dr. Aznizam bin Abu Bakar for his guidance and advice in teaching this subject (PRINCIPLE OF CHEMICAL ENGINEERING). This semester only four chapter were covered which are Balances on Nonreactive Processes, Balances on Reactive Processes, The second law of Thermodynamics and Power and Refrigeration System.

Balances on Nonreactive Processes 

This chapter presents on how to evaluate enthalpy change or internal energy change. Once these calculations have been performed, the energy balance can be solved as before. In this chapter, I learn how to construct hypothetical path. When a species passes from one state to another, enthalpy or internal energy surely will be changed. Enthalpy and internal energy depends on temperature and state of aggregation. Change on pressure does not affect the value of enthalpy and internal energy.

In order to calculate enthalpy at different temperature, we have to know the value of Cp (Heat Capacity). Cp already given in the reference book. However, Cp data for some compounds are absence and we have to estimate  the value by using Koop’s Law. Moreover, this chapter also expose me the definition of latent heat and it can be estimate by using Trouton’s Rule, Chen’s Equation, Clapeyron Equation and Watson’s correlation. Psychometric chart or also known as humidity chart is used to determine and calculate the absolute humidity, dew point temperature, wet bulb temperature, relative humidity and humid volume.

For this third semester, I should take the subject of principles of chemical process 2 which is also famous with the name of energy balances and also learn about thermodynamics in this subject. For the first class of pcp 2 with Dr aznizam I very excited to get lecture from dr because I heard dr is very energetic, funny, best of lecture that give us more explanations to understand the topic. The topic that I learnt from the first class of this semester is about open and close system which is done with last semester but dr want to remind back what i have learnt before to relate for next topic of balances on nonreactive processes. I also learnt about hypothetical process path construction which is should do when have changes of phase and to get the enthalpy.

For the next class, I learnt about how to calculate enthalpy using the formula of integration based on table b1 n b2 and so on. Dr gives us a lot of exercise, exercise one until exercise five. Even class was cancel for the third class we have the task to complete the quiz and exercise. As advice that dr give, ”when a person wants to do something in life , then all the excuses go away automatically, but the first step has to  be taken. The first step and focus is what keeps on going. Thankz dr..

Today I learn how to create my own portfolio. When I was informed that I have to attend this course,I don't want to come to this class.But,since i have come to this course,i think this is the best way to save and store my education files,my information and this system is seems like fb..