Posted on Categories:Thermodynamics, 热力学, 物理代写

# 物理代写|热力学作业代写THERMODYNAMICS代考|MAE204 What Is a Molar Balance on the Amount of Substance?

avatest™

热力学Thermodynamics在热力学中，大型物体集合体之间的相互作用被研究和归类。这方面的核心是热力学系统及其周围环境的概念。一个系统是由粒子组成的，其平均运动定义了它的属性，而这些属性又通过状态方程相互关联。属性可以结合起来表达内能和热力学势，这对确定平衡和自发过程的条件很有用。

avatest.org 热力学Thermodynamics作业代写，免费提交作业要求， 满意后付款，成绩80\%以下全额退款，安全省心无顾虑。专业硕 博写手团队，所有订单可靠准时，保证 100% 原创。avatest.org™， 最高质量的热力学Thermodynamics作业代写，服务覆盖北美、欧洲、澳洲等 国家。 在代写价格方面，考虑到同学们的经济条件，在保障代写质量的前提下，我们为客户提供最合理的价格。 由于统计Statistics作业种类很多，同时其中的大部分作业在字数上都没有具体要求，因此热力学Thermodynamics作业代写的价格不固定。通常在经济学专家查看完作业要求之后会给出报价。作业难度和截止日期对价格也有很大的影响。

avatest.org™ 为您的留学生涯保驾护航 在物理physics作业代写方面已经树立了自己的口碑, 保证靠谱, 高质且原创的物理physics代写服务。我们的专家在热力学Thermodynamics代写方面经验极为丰富，各种热力学Thermodynamics相关的作业也就用不着 说。

## 物理代写|热力学作业代写THERMODYNAMICS代考|What Is a Molar Balance on the Amount of Substance?

A differential molar balance for the amount of substance B in a closed system of volume, $V$, can be formulated as
$$\mathrm{d} n_{\mathrm{B}}=v_{\mathrm{B}} r V \mathrm{~d} t,$$
where $\mathrm{d} n_{\mathrm{B}}$ is the molar accumulation of $\mathrm{B}$ in the system in moles. The right-hand side of the equation does not account for $B$ exchanged with the environment, because the system is assumed to be closed. But in contrast to the mass balance, a molar balance for a given substance contains a source term, because B could be synthesized or consumed inside the system through a chemical reaction. This term appears on the right side and expresses the infinitesimal number of moles of $B$ produced or consumed during an infinitesimal time span $\mathrm{d} t . v_{\mathrm{B}}$ represents the stoichiometric coefficient of $\mathrm{B}$ in the chemical reaction and $r$ the reaction rate in $\mathrm{mol} \mathrm{s}^{-1} \mathrm{~m}^{-3}$. As explained in connection with Equation 1.31, the stoichiometric coefficient is positive if $B$ is a product but negative if it is a reactant. In the latter case, B is consumed by the chemical reaction and one would speak of a sink rather than of a source. The integrated balance can be formulated as
$$\Delta n_{\mathrm{B}}=\nu_{\mathrm{B}} \int_{0}^{t} r V \mathrm{~d} t .$$
Comparing this to the definition of the extent of chemical reaction (Equation 1.31) shows
$$\int_{0}^{t} r V \mathrm{~d} t=\xi \quad \text { or } \quad V r=\dot{\xi} .$$

## 物理代写|热力学作业代写THERMODYNAMICS代考|What Is Internal, or Thermodynamic, Energy? What Is an Energy Balance for a Closed System?

In mechanical systems, energy is stored primarily in the form of potential and kinetic energy. In thermodynamic systems, however, the most important form of energy is often the so-called internal or thermodynamic energy. This comprises all forms of energy stored at the molecular level in force fields such as attraction and repulsion forces, the force required to create a surface, the kinetic energy of the molecules themselves moving around at a certain temperature and so on (see Question 2.5). It is called thermodynamic or internal energy $U$ and quantified in joules.

The internal energy of a closed system can be increased by adding energy to it in the form of heat $(\delta Q)$, volume work $(-p \mathrm{~d} V)$ or other work ( $\left.\delta W_{\mathrm{o}}\right)$ (see Questions 1.3.6 and 1.3.7). Hence, the energy balance of a closed system is
$$\mathrm{d} U=\delta Q-p \mathrm{~d} V+\delta W_{0}$$
or
$$\Delta U=Q-\int p \mathrm{~d} V+W_{0}$$

## 物理代写|热力学作业代写THERMODYNAMICS代考|What Is a Molar Balance on the Amount of Substance?

$$\mathrm{d} n_{\mathrm{B}}=v_{\mathrm{B}} r V \mathrm{~d} t$$

$$\Delta n_{\mathrm{B}}=\nu_{\mathrm{B}} \int_{0}^{t} r V \mathrm{~d} t$$

$$\int_{0}^{t} r V \mathrm{~d} t=\xi \quad \text { or } \quad V r=\dot{\xi}$$

## 物理代写|热力学作业代写 THERMODYNAMICS代考|What Is Internal, or Thermodynamic, Energy? What Is an Energy Balance for a Closed System?

$$\mathrm{d} U=\delta Q-p \mathrm{~d} V+\delta W_{0}$$

$$\Delta U=Q-\int p \mathrm{~d} V+W_{0}$$

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。