Questions relating to heat and its relation to other forms of energy in chemistry.

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If we mix Ice and water (both at 0 degree Celsius), does their quantity remain constant?

I was wondering that whether Ice and water mixed (both at 0 degree Celsius) undergo a change in their concentration or not. If not, then does it has nothing to do with equilibrium constant? ...
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Will all thermodynamic equations have a linear dependence with moles?

I'm taking chemical thermodynamics this semester, and currently seeing things like the Maxwell's Relations. My professor never uses explicitly the variable "n" and always works with molar quantities ...
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condensation of tellurium on inside of ampoule?

After heating an ampoule of tellurium around its melting point in a furnace for about a day, I've noticed drops of the element on the upper inside surface of the ampoule, as if it condensed there. ...
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Ideal gasses reaction under const temp and pressure

Conceptual problem: let $A + 2B \rightarrow C + 2D$ be a reaction under constant pressure (P) and temp (T), that goes all the way towards the products. A,B,C,D are ideal gases. let $\Delta H$ be the ...
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23 views

Pre heat coal before burning

So I was wondering if pre-heating coal will improve the efficiency of a steam boiler. I did find that intake air pre-heater and water pre-heater do increase efficiency, but I could not find anything ...
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257 views

Why is the specific heat of water high?

How is the specific heat of water so high? I was reading the hyperphysics article on it but could not understand it properly.
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How do I determine if a process is reversible without numeric information?

How do I determine if a process is reversible without numeric information? It would be nice to know how to determine whether a process is reversible in order to solve problems LIKE this one: A ...
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1answer
32 views

Deriving The Triple Point Temperature and Pressure as the following expression

$ΔH_{fus}, ΔH_{vap}, ΔH_{sub}$, as well as ($Tl,Pl$) and ($Ts,Ps$), which corresponds to the temperature and vapor pressure of liquid and solid phrase. My strategies is to use the Clausius-Clapeyron ...
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Is delta H a state function?

My teacher says $H$ is a state function but $\Delta H$ is not. But I think both of them should be state function. Is he correct?
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Why does the sodium acetate solution crystallize by touching? [closed]

As the title stated above, why and how does the sodium acetate solution crystallize by touching?
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What is the partial molar volume of epsomite (magnesium sulfate heptahydrate)?

I am trying to calculate the expected volume of an aqueous solution of epsomite and NaCl (308 deg K but willing to go with 298 K as close enough, and 1 atmosphere pressure). I realize the two may ...
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How do things heat one another? [duplicate]

For example, how does a gas stove heat a metal pot? A combustion reaction between the gas and the air takes place, and this releases energy due to new chemical bonds being formed. Do the atoms in ...
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1answer
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How can enthalpy of a system be negative while entropy is positive?

ΔG = ΔH(system)-TΔS(system) ) When enthalpy is negative, the reaction is exothermic, which means it releases energy into the surroundings. If the system is losing energy, shouldn't the entropy of ...
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Entropy change of system in adiabatic irreversible process [duplicate]

In an adiabatic irreversible process we know that q = 0. Now change in entropy is defined as q/T. So when q is zero, why is change in entropy not zero ?
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1answer
41 views

Why does temperature affect cell potential?

The Nernst equation describes the relationship between cell potential and temperature. But why does temperature affect cell potential? My understanding is that the collision model of kinetics is not ...
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2answers
29 views

Why is the volume in this compress gas cylinder constant throughout?

I am stuck on this gas question and its really stressing me out. A compressed cylinder of gas contains $2.25 \cdot 10^3~\mathrm{g}$ of $\ce{N2}$ gas at a pressure of $4.25 \cdot ...
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How are pressure vessels heated?

I'm working on a project in which I'll be dealing with pressure vessels. As of now I've drawn/conceptualized everything on theory basis. The diagrams are made on the basis of theory, but then I came ...
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2answers
84 views

Gibbs Free Energy

My teacher said that : The decrease in Gibbs free energy is the maximum non-mechanical work that can be obtained when the process occurs reversibly at constant temperature and pressure But for ...
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1answer
12 views

kinetic and thermodynamic parameters of biodiesel production from lard

I want to know if someone has experimental results and calculations of the kinetic and thermodynamic parameters of Base Catalyzed Transesterification of pig fat, if not which is the method used to ...
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1answer
29 views

What is the temperature of heat generated from LPG gas?

I'm working on a project and I require around 300-400 degree Celsius of temperature. As of now I'm taking the normal LPG gas that is available in our house for cooking purposes for my project, but I'm ...
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67 views

Kinetics vs Thermodynamics

The way kinetics is taught at the undergraduate level (Arrhenius and collision theory) chemical equilibrium is determined governed immensely by activation energy of the reaction. According to ...
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1answer
22 views

Thermodynamic properties software

I am looking for a software (can be freeware or purchased) to look up water and steam thermodynamic properties (e.g. density, enthalpy, entropy) preferably a macro in excel. What do you use for this ...
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1answer
35 views

Helium gas expand isobaric isothermal

If 4 mol helium gas expand against constant pressure in isothermal process. How can calculate w? Is it w=-nrtLn(v2:v1) as define by isothermal or is it w=-p(v2-v1)as define from isobaric? Also, is ...
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Is there a difference between Joule coefficient and Joule-Thomson coefficient?

Is there a difference between the Joule coefficient and the Joule-Thomson coefficient? Also, I am having a hard time understanding what they mean.
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What does Gibbs free energy exactly mean? [duplicate]

What is Gibbs free energy? What is change in Gibbs free energy, Why it should be always negative? Why change in entropy should be always positive? Can anyone explain the physical significance of these ...
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1answer
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LiAlH4 / H2O reaction energy

I'm dealing with a free-energy scam on another forum. It is well-known that $\ce{LiAlH4}$ reacts explosively with water. My chemistry days are long behind me, so I thought I'd come here to ask: ...
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2answers
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Gibbs free energy or reaction enthalphy

If I conduct a reaction say, $$\ce{CaO(s) + H2O(l) \rightarrow Ca(OH)2 (aq)}$$ let us say , I want to measure the energy generated from the reaction.Will this energy I calculate equal the change in ...
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Formula of entropy change

In my 12th standard book , the formula for entropy change is given as $\Delta S = \frac{q(reversible)}{T}$, what is the importance of absorbing heat reversibly , why not irreversibly? & what does ...
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Does the speed of an ion affect the current that can flow through a solution?

Typically, when a cathode and anode are inserted into a solution that allows current to flow, the ions are moving with a certain kinetic energy. If the ions were to gain kinetic energy (through ...
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What's the name of the problem of finding equilibrium concentrations?

Is there any specific name of the problem of finding equilibrium concentrations with known equilibrium constants and initial concentrations? Would it be appropriate to call it "direct equilibrium ...
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1answer
58 views

Why do internal combustion engines only burn to carbon monoxide, not dioxide?

Why don't diesel and regular car engines burn all the way to $\ce{CO2}$?
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1answer
50 views

Magnetic stirrer with hot plate

I did not know there are products such as a magnetic stirrer with a hot plate, enabling one to apply heat and stirring to a solution with relative ease. Did I understand correctly, that device needs a ...
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1k views

Temperature of an atom

I read somewhere that the temperature of an atom is not defined. The definition of temperature is only for larger systems. Why is this so?
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What is an example of a very low temperature endothermic reaction?

Shakashiri describes the reaction of solid Ammonium Thiocyanate and solid Barium Hydroxide Octahydrate resulting in an endothermic reaction leading to subzero temperatures. I've performed this ...
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Gibbs Free Energy : What is it trying to say actually?

"Gibbs Energy is the useful work that can be extracted from the heat of a rxn or a thermodynamic process." I understand how it predicts the feasibility of a chemical rxn, considering the Entropy ...
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1answer
64 views

How to calculate the heat capacity of a calorimeter?

I need to find the heat lost of an unknown metal dropped into a calorimeter with $70~\mathrm{g}$ $\ce{H2O}$. The initial temperature and final temperature of the $70~\mathrm{g}$ $\ce{H2O}$ and the ...
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Vacuum good inside a box?

I have no clue whatsoever about Chemistry on a academic point of view. We wish to transport some goods. Let's say we vacuum some of those goods, by doing like so: We place those goods on a box, we ...
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1answer
64 views

Reversible thermodynamic machine

Assume two identical solid blocks of copper with molar heat capacity at constant volume $C_{V,m}=24.5 \text{ J$\cdot$K$^{-1}$mol$^{-1}$}$ . Assume the heat capacity to be constant in the ...
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1answer
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Good choice for heat-conductive coil submerged in sea water

I know only as much about chemistry as I can remember from a year in college. So, please speak slowly and use short words. I'm trying to decide on an appropriate material for a heat-transfer coil ...
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Gibbs energy and Entropy

In Gibbs energy equation- $\Delta G= \Delta H - T \Delta S$ At constant pressure, $Q=\Delta H$ (1) and we know that $T \Delta S = Q$ (reversible) so finally $T \Delta S=Q$ (2) Putting values ...
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What's sulphur's state of aggregation in petroleum?

Using google, I wasn't able to find an answer to this question. Conditions: p = 1 bar and T = 298 K.
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Why does the Born equation give the Gibbs free energy of solvation rather than enthalpy of solvation?

The Born equation gives the difference in energy required to charge a particle in a vacuum and in solution which results in the work required to transfer an ion from a vacuum into solution. It is ...
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52 views

What happens to energy changes in non-reversible processes?

Take internal energy for example: $$dU\leq TdS-PdV$$ Firstly, I would like to make clear that the following question/argument relies on the following statement being correct: the left hand side of the ...
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For a system to undergo a spontaneous change at constant temperature and pressure the Gibbs free energy must decrease, but how?

$$dG<VdP-SdT$$ So for a process at a constant pressure and temperature, and in the absence of any non-pV work, $dG<0$. Since energy cannot be created or destroyed (and Gibbs free energy is a ...
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Are the values for enthalpy, internal energy and Gibbs free energy the same for a particular process?

Internal energy, enthalpy and Gibbs free energy are all units of energy. So, for any particular process where energy is lost from the system the same amount is given off to the surroundings. Am I ...
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Whats the difference between entropy and the (dis)order of a system?

Entropy is often verbally described as the order/disorder of the thermodynamic system. However, I've been told that this description is a vague "hand-waving" attempt at describing what entropy is. For ...
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How does the chemical potential allow for open systems to be considered?

Gibbs free energy can be defined as: $$dG=VdP-SdT+\sum_i\mu_idn_i$$ where $\mu=(\frac{\partial G}{\partial n})_{P,T}$. Last term, $\sum_i\mu_idn_i$ allows for open systems to be considered (where $dn$ ...
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Gibbs free energy can be expressed as a function of P,T and n but are enthalpy and internal energy also (partially) functions of n?

$$G=G(P,T,n)$$ $$dG=VdP-SdT+\mu dn=(\frac{\partial G}{\partial P})_{T,n}dP+(\frac{\partial G}{\partial T})_{P,n}dT+(\frac{\partial G}{\partial n})_{T,P}dn$$ This allows open systems to be considered ...
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Can state of matter from liquid to gas maintain the same molecular structure in PE or in polymers in general, like water does?

If I’ve got a reactor containing PE-Polyethylene $(\ce{{C2}$H_\text{4})n$}$ (solid) and the rest is filled with nitrogen gas. The system is closed. Supposing we have an initial temperature of ...
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If the standard state symbol means that the substance is pure (and at 1 bar) how is it possible to have a standard REACTION enthalpy?

For the reaction one mole of substance $A$ in equilibrium with one mole of substance $B$ the standard reaction enthalpy is defined: $$\triangle_rH^{\theta}(T)=H_m^{\theta}(B;T)-H_m^{\theta}(A;T)$$ ...