Questions tagged [heat]
For questions about heat - a form of transfer of energy from one body to another or from one body to its surroundings. Also see these tags: [thermodynamics], [enthalpy], [energy], [temperature].
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Why can we only measure heat and not temperature?
I'm taking chemistry for the first time next semester, so a friend bought me a textbook on the subject. It should probably be mentioned that this textbook is non-traditional, called Chemistry: a Novel ...
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Attempt at proof - how to proceed in proof that dG<0 for a spontaneous reaction?
I have been studying thermodynamics for a few weeks now and am thinking about its applications in chemistry as I am a chemistry undergraduate. In particular, I wanted to derive the criterion for ...
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Why is the transfer of heat across a finite temperature difference irreversible (without using entropy)?
I get the entropy explanation of why heat transfer across a finite temperature difference is irreversible: there is entropy production which makes it irreversible. But, irreversibility can also be ...
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Alternative Explanation to Why is Entropy Zero in a Reversible Adiabatic Process?
We know that heat is a disordered way of energy transfer and work on the other hand is an ordered way of energy transfer. Since in a reversible adiabatic process, there is no transfer of heat and only ...
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Assumptions in defining the change in entropy of the surroundings
I have seen many varients of this question such as here and here, but the answers do not really answer my question.
In the explanation that $\Delta S_{\mathrm{surr}}=\frac{q_\mathrm{surr}}{T_\mathrm{...
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Is entropy constant when no heat is transferred?
Does entropy remain constant in when no heat is transferred between the system and surroundings?
If I do only mechanical or electrical work to change the properties like the volume of the system, ...
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Deriving the relationship of Cp - Cv in terms of P, T, V, and H
We're learning the relationship between $C_P$ and $C_V$. We seem to be doing it a little uniquely because we're looking for equations of $C_P - C_V$ in terms of $P, T, V$ and $U$ and in terms of $P, T,...
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Entropy change in isothermal reversible expansion
So, this question is of JEE Mains 2023 exams.
One mole of an ideal gas at $350K$ is in a $2.0L$ vessel of thermally conducting walls, which are in contact with the surroundings. It undergoes ...
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How to calculate the specific heat capacity of a non-ideal heterogenous mixture/suspension with four components?
I need to calculate the specific heat capacity of a non-ideal mixture of glycerol (liquid), ammonia (liquid), water (liquid) and biomass (solid). What would be the best way to approximate the specific ...
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Can liquid hydrogen be oriented along a single axis?
I ran into a fascinating little fact I didn't remember hearing before: if H2 is cooled below 60 K, its heat capacity looks like that of a monoatomic gas. It simply doesn't have enough thermal energy ...
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Is there water coloring that will maintain color at 80°C?
I'm building a keg cleaner for my employer. The cleaner has a caustic tank that uses PBW, and a sanitizer tank. The current build is plagued with caustic contamination, so I would like to see ...
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Theoretical justification for the definition of standard enthalpy of reaction
I've been reading the book Chemistry: Core Concepts by Allan Blackman, Daniel Southam, Gwendolyn Lawrie, Natalie Williamson, Christopher Thompson and Adam Bridgeman. They give the following definition ...
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Calculating the heat of reaction between sulfuric acid and sodium hydroxide
For my lab report I have to calculate the theoretical heat of reaction $\Delta H_{\text{rxn}}$ between sulfuric acid $\ce{H2SO4}$ and sodium hydroxide $\ce{NaOH}$ using their heat of formations. The ...
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Two different approaches for calculating enthalpy change for methane + HCl
I know that $\Delta{H}=H_{products}-H_{reactants}$ and also we can use $\Delta{H}=\Sigma{H}_{bonds broken}-\Sigma{H}_{bonds formed}$.
Take the example of methane + HCl. If you calculate the total ...
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Why are internal energy and work mentioned in a question about exothermic or endothermic systems? [closed]
This is a question from my chemistry homework. Note the explanation below.
A 100.0-g bar of gold is heated from 25°C to 50°C during which it absorbs 322 J of heat. The volume of the gold bar remains ...
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