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

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what is the fastest way to evaporate 150 ml of water using only heat from the sun and what is the rate of evaporation [on hold]

This isn't for a project or question or anything, I'm just curious. Basically the question is what is the fastest rate of evaporation that can be achieved using only solar heat on a constantly ...
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1answer
31 views

Is the deprotonation of phenol exothermic?

I just wanted to confirm that deprotonation reaction of weak acids are exothermic? I know that strong acids deprotonate exothermically (e.g. adding liquid $\ce{H2SO4}$ to water releases a lot of heat),...
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3answers
44 views

Work and entropy

I am not able to conceive why work wouldn't increase the entropy of a system. If i am compressing a ideal gas adiabatically and reversibly, the gas pressure inside would increase,meaning more no of ...
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10 views

Heat of reaction at constant pressure and constant volume [closed]

When 1mole of liquid benzene is completely burned in oxygen to form liquid water and carbon dioxide gas change in enthalpy is -3264.58kj at 298k calculate the enthalpy of reaction at constant volume ...
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4answers
872 views

Why does entropy increase when the difference in temperatures is decreased?

In irreversible heat transfer, heat energy is irreversibly transferred from the higher temperature system to the lower temperature system, and the combined entropy of the systems increases. Source: ...
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Hi, I need to plot S = k log W against T in Kelvin from T=0 to T=100 [closed]

I need to plot S = k log W against T in Kelvin from T=0 to T=100 for CO HCl Can anyone help me understand the relation between W and CO/HCl?
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2answers
33 views

Is there a way to counteract the problems with weighing hot objects?

I am currently performing an experiment in which it would be greatly beneficial to be able to accurately measure the mass of a hot object without waiting for it to cool. The current plan is simply to ...
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2answers
53 views

Can equilibrium be reached in a non-reversible chemical reaction?

Can chemical equilibrium only be achieved in a reversible process? I have only seen equilibrium in processes that are reversible so I was wondering if it were possible in reactions that are not ...
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2answers
125 views

Does ∆Gº exist?

To the best of my understanding, the quantity of Gibbs free energy of an entity depends on its concentration in the system. Equilibrium is reached when ∆G = 0, or when the Gibbs free energies of all ...
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33 views

Derivation of the Lever Rule

To derive the Lever rule, the textbook I am reading sets: $$nz_A = n_\alpha x_A + n_\beta y_A\\ nz_A = n_\alpha z_A + n_\beta z_A$$ $x_A =$ liquid phase mole fraction of component $A$ $y_A =$ gas ...
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1answer
57 views

Why are non-spontaneous reactions driven in the presence of energy?

Here is my understanding. If you have an endergonic reaction (m) with $\Delta G_m=-m$ and you couple it to an exergonic reaction (n) with $\Delta G_n=n$, where $n>m$, then the endergonic reaction ...
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1answer
55 views

Immersing copper and zinc in hydrochloric acid

I am wondering what would happen if a metal strip of copper and a metal strip of zinc were immersed in solution of $\ce{HCl}$ in standard electrochemical conditions. I have calculated the standard ...
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65 views

Decomposition of CaCO3 in a sealed vessel

For the equilibrium $$\ce{CaCO3(s) <=> CaO(s) + CO2(g)}$$ $\Delta H^\ominus = 178\ \mathrm{kJ\ mol^{-1}}$ and $\Delta S^\ominus = 160\ \mathrm{J\ mol^{-1}}$. I'm asked to suppose that $1\ \...
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3answers
69 views

Is ΔS of a system related to temperature and change in enthalpy?

I often see the equation $\Delta S_\text{universe}$ = $\Delta S_\text{surroundings}$ + $\Delta S_\text{system}$, where $\Delta S_\text{surroundings}$ can be re-expressed as $\dfrac{-\Delta H_\text{...
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1answer
46 views

What is the solution to Kauzmann's paradox?

Kauzmann's paradox is the paradox of what happens when a liquid is supercooled below the temperature at which the difference in entropy is zero.
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25 views

Triple Point Equation

Is there any equation that can calculate the triple point of a substance? Because a method for calculating the critical temperature and the Boyle temperature of a substance that I posted in another ...
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19 views

Why is the specific heat of ethanol not representing experiments

I am in my last year of high school completing an assignment hot and cold packs, and particular the enthalpy behind them. My major lack of understanding is why my calculations are working for heat of ...
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1answer
36 views

What really is an equation of state (EOS) and how are they developed?

Are EOSs merely correlations that mathematically represent (in a better or worse way) experimental data or do they have a theoretical background? How are they developed (suppose one wishes to develop ...
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1answer
33 views

Hess's Law/Enthalpy of reaction problem

The problem: Chloroform, $\ce{CHCl3}$, is formed from methane and chlorine in the following reaction: $$\ce{CH4(g) + 3Cl2(g) ->3HCl(g) + CHCl3(g)}$$ Calculate $\Delta rH^{\circ}$, ...
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1answer
15 views

Difference between free energy of formation and free energy of combustion [closed]

I was wondering what is the main difference among those two values.
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0answers
17 views

Heating of mixture of gases with one gas barely above its boiling point

What happens when mixture of two gases is heated in a closed container? If one gas expands faster than the other and increases pressure of the container enough so that the boiling point of the other ...
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0answers
20 views

Question on surface tension and adsorption

I just read that positive adsorption is observed with solutes which are hydrophobic when water is the solvent, and alcohol in water is given as an example (which was then generalized as polar organic ...
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2answers
38 views

How to obtain saturated pressure of water at 200 ºC using fugacities

The target is to obtain saturated pressure of water at 200 ºC using PHI-PHI (fugacity coefficients) approach,so it means it's a VLE of water only,so we write equilibrium condition: $f_i(l)=f_i(v)$ (*)...
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1answer
33 views

Decomposing chemical compounds - Ease of Decomposition [closed]

Someone asked me a question, that which of the following can be decomposed chemically: Ammonia Iron Neon Hydrogen Flourine My Analysis: At first attempt I answered Ammonia but changed it to 'I ...
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Why don't we equate ΔH or some other thermodynamic quantity with -nFE and instead use ΔG?

I was studying electrochemistry, and the very first equation that I came across was this, with no proof. $$\Delta G = -nFE$$The only explanation that was given was that the change in Gibb's free ...
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1answer
40 views

What is the difference between the chemical potential μ and the molar Gibbs free energy Gm?

I'm not too sure if I understand this correctly: Is the $G_\mathrm{m}$, the Gibbs free energy of the entire system, divided by the amount of substance making up the system, while $\mu$ is the Gibbs ...
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1answer
59 views

How to derive Van't Hoff equation for Henry's constant

While studying about Henry's Law, I encountered this equation,I didn't know how to derive it so I searched about it and got nothing, I tried to substitute $H$ (Henry's const.) by $\gamma\cdot f_i$ ...
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1answer
43 views

Heat Transfer during Phase Change

When ice is melting, we know that the temperature stays constant at 0 ℃. If we were to place ice at 0 ℃ in a sufficient amount of water at ambient temperature, would the temperature of the water ...
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12 views

How is temperature dependency on pressure measured in an adiabatic process experimentally?

I've been studying Maxwell's equations recently. While solving some exercises, I stumbled upon the expression of the dependency of temperature regarding pressure at constant entropy: $$\frac{∂T}{∂P}∣...
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1answer
38 views

Mass of Ice during Phase Change

If 18g of ice at a temperature of -6 ℃ is placed in 250 g of water at 20 ℃, we know that there is enough energy supplied by the water to completely melt the ice and transform it into liquid. My ...
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2answers
55 views

What is at 298 K at standard entropy?

The standard entropy of a substance is the entropy of $1$ mol at $298$K and $1$ bar pressure. What exactly is at $298$K? The system or the surrounding? Let's take vapour as an example where $ \ \ce{...
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34 views

Entropy Change of Resistor

A very large swimming pool filled with water of temperature equal to $20\mathrm{^\circ C}$ is heated by a resistor with a heating power of $500\ \mathrm{W}$ for $20$ minutes. Assuming the water in ...
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247 views

Is the final temperature of a solution affected by the order of mixing components?

For example, I have two beakers each containing water. One is at 90 $^{\circ}$C and one is at 10 ${^\circ}$C. Will the final temperature of the solution I make from mixing the two components be ...
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1answer
50 views

Do all adiabatic processes involve a change in temperature?

I learnt that adiabatic processes involve no heat exchange between the system and the environment. Does this mean that all adiabatic processes involve some changes in temperature then? Thanks a lot!
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29 views

Latent Heat and Kinetic Energy

The kinetic theory says that temperature is the measure of the average kinetic energy. That would mean then : The temperature rises with the rise in kinetic energy. We know that when matter changes ...
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11 views

Generalized enthalpy of vaporization for corresponding states

I'm interested in equations for substances at corresponding states that give general relationships between common chemical and physical properties. For example, the Guggenheim equation for saturation ...
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33 views

How can change in gibbs free energy be greater than enthalpy?

There is a problem in the textbook I'm studying Chemistry from that although was easy to compute, the result surprised me conceptually: The standard enthalpy for a reaction is said to be: -115kJ, we ...
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22 views

Doubt on Graham's Law of diffusion

Let's say i have two gases in 2 different containers ( with different temperature values ) And i want to compare the respective rates of diffusion. at time=$t$ , would the ratio $ \frac{r_1}{r_2} $ ...
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21 views

Heat Retaining Capacity

Specific Heat Capacity is the heat required to raise the temperature of 1Kg of substance by 1degree celsius. Is there any metric to measure "Heat Retaining Capacity" of a substance? Something like "...
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1answer
39 views

shifting of equilibrium

Does it mean that if one side of a reaction is favoured, the reaction will shift to the other side? As I was reading up on the van't Hoff equation, it says that an increase in temperature of an ...
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1answer
73 views

Is there a substance I can use to coat a projectile to eliminate friction heat?

Let's say that I was going to shoot a can of beer into space from one of those "vacuum cannons." I would expect that the friction with the air around the projectile would cause the whole thing to just ...
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0answers
22 views

Hydrazine vs 1,1-dimethylhydrazine for rocket fuel?

The question in my textbook is as follows: Hydrazine and 1,1-dimethylhydrazine both react spontaneously with O2 and can be used as rocket fuels. $$\ce{ N2H4(l) + O2(g) -> N2(g) + 2H2O(g)...
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23 views

How to evaluate standard enthalpy, standard entropy and standard free energy in a temperature different that 298K

A question is asking me to calculate the equilibrium constant of a given reaction of gases at 373 K. My immediate thought was to think about van't Hoff equation: $K_p=e^{\frac{-\Delta G^0}{RT}}$ ...
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1answer
58 views

Does entropy depends on temperature?

Does the entropy of a system depends on the system's temperature? I know that $\Delta S_{ext}=\frac{q_{rev}}{T}$ ($q_{rev}$ is the heat in a transformation if it is reversible). My textbook says ...
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26 views

potential profile in kinetics and spontaneity in reactions

We usually think of the criterion of spontaneity of a reaction as the change of Gibbs energy. By Clausius inequality, one of various forms of the 2nd law, we know that $ \mathrm{d}S-\frac{\mathrm{d}H}...
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21 views

Why does aluminum have a higher thermal conductivity than tin?

I initially believed that tin would have a higher thermal conductivity because it is more dense but I found out I was wrong and I'm wondering why.
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37 views

Why in thermodynamics, some reactions are taken at constant temperature and pressure? What is its significance?

To be more specific while deriving relation between cell emf and free energy, constant temperature and pressure assumptions were taken. Why?
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19 views

Mid point reduction potential

A solution of $100\ \mu \mathrm{mol\ L^{-1}}$ nicotinamide adenine dinucleotide has an absorbance of $340\ \mathrm{nm}$ of zero when in the $100\%$ oxidized form and $0.0622$ when in the $100\%$ ...
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20 views

Microstates, molar mass, and degrees of freedom.

What is the relationship between the number of microstates and molar mass. The key says choices II and III are correct. If III is true, why isn't I also true? Also, if II is true, why isn't IV true as ...
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1answer
27 views

Temperature and reaction quotient

Consider an exothermic reaction. If we double the temperature at which the reaction is run, will the reaction quotient increase? I know that an increase in Q relative to K causes the reaction to ...