Questions tagged [temperature]

A measure of the average kinetic energy of the particles in a sample of matter; may be expressed either in kelvin (symbol K) or in degree Celsius (symbol °C).

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Calculation of Volume using Van Der Waals equation of state [closed]

It is necessary to provide a chemical factory with a tank sufficient volume to store 100 moles of a pressure of 2.50×10⁶ Nm‐² at 298K. Calculate the volume that the tank should possess according to ...
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Raising melting point of water at STP (using disolved impurities)

Typically, water experiences melting point depression when it is impure. The more impure it is, the lower the melting point, up to a point. I understand you could raise the melting point by increasing ...
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Relation between common ion effect and the temperature of the solution [closed]

Adding extra Na+ in a saturated NaCl/water solution decreases the solubility of NaCl. How does this exactly happen? AFAIK, the solubility of a solid only decreases with the temperature of the solution....
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Constraints on pyrotechnic explosives that won't detonate spontaneously at 500 °C when landing on Venus?

The Space Exploration SE question Premature detonation of explosive bolts when landing on hot Venus? explains the need for and widespread use of pyrotechnic fasteners and cable cutters for Mars ...
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Heat released at constant pressure and temperature and heat released at constant density and temperature

Is there a relation between heat released at constant pressure and temperature and heat released at constant density and temperature? I was reading some books on propulsion and combustion, and the ...
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Entropy change during electrolysis of water

Consider the electrolysis of water reaction: $$\ce{H_2O -> H_2 + 1/2O_2}$$ At room temperature and atmospheric pressure, the change in enthalpy of this reaction is $\Delta H = \pu{+286 kJ mol-1}$. ...
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How to heat up a barrel drum? [closed]

I am experimentalist, and I am unsure on how to proceed about a question I have for an experiment. In the experiment, I would like to heat up a drum barrel like: It is made of HDPE, and I would like ...
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Energy Balance for a reactor [closed]

There's wastewater flowing into the reactor at $\pu{20 ^\circ C}$ and the reactor is maintained at $\pu{36 ^\circ C}$. The effluent of the reactor flows into the stripper, which is at $\pu{65 ^\circ C}...
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Sound absorption in carbon dioxide with temperature

I am doing speed of sound measurements in $\ce{CO2}$ using ultrasonic pulses at 125 kHz. $\ce{CO2}$ is particularly difficult because it strongly absorbs ultrasound due to its multiple vibrational ...
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Calculate Specific Heat given initial temp, final temp and equilibrium temp [closed]

I would appreciate if someone could enlighten me on this question. Question: A metallic object with a mass of 2 kg at 50ºC is placed in 10 L of water at 20ºC. When the thermal equilibrium the ...
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Pressure of two flasks connected to each other at different temperatures [closed]

Two flasks of equal volume connected by a narrow tube (of negligible volume) are at $\pu{27 °C}$ and contain $\pu{0.7 mol}$ of $\ce{H2}$ at $\pu{0.5 atm}$. If one of the flasks is then immersed into a ...
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Why isn't entropy dimensionless?

The usual units are J/K, however the only reason temperature has different units than energy is because we didn't used to know temperature was just the average kinetic energy of atoms/molecules. ...
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is electrolysis of water less efficient with warm water? E.g 40, 50, 60… °C

I see there is High-temperature electrolysis which is a whole different animal than room temp electrolysis. I want to know if electrolysis of lukewarm water will behave much differently. My guess is ...
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In an closed adiabatic container, if we carry out an exothermic process, what will happen to the temperature of the system

I know that a closed adiabatic container acts as an isolated system, so I expect the internal energy of the system to be a constant as in an isolated system. But since it is an exothermic reaction, ...
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What is the difference between “vapour” and “gas”?

I have read the definition of vapour on Wikipedia, but I don't seem to have a clear idea about the difference between a vapour and a gas. I know what it means when it says, "gas at a temperature ...
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Liquifying a gas above critical temperature [duplicate]

Is there any theoretical/hypothetical way through which a gas can be liquified above critical temperature? For example applying inifinjte amount of pressure to the system?
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Cooling down from −78 °C to −88 °C without cryogenics

Say I have a gas cylinder with nitrous oxide and cool it down to −78 °C with dry ice. Is there an endothermic process/reaction that would extract the remaining heat from $\ce{N2O}$ and bring it down ...
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Does the anti-rust properties of bluing carbon steel disappear at a certain temperature?

Yesterday I blued my new carbon steel wok over a very high (200K BTU) burner which is capable of getting the wok to 1000+ degrees with ease. I understand that bluing adds a rust-resistant layer which ...
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What pressure does liquid nitrous oxide need at −45 °C?

What pressure does liquid nitrous oxide need at −45 °C to remain liquid? How can I calculate its pressure required for other temperatures?
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Is it possible to store moist air at high pressure?

Is there any way to store moist air inside a high pressure tank? Let's suppose that I have humid air (30%) at room temperature and I want to store it at 300Bar in a tank. when I extract the fluid from ...
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pKw, pKb, pKa and NEN6411

I am trying to understand how to account for pH-temperature relations during industrial pH measurements. Do I have it right?: The impact temperature has on the pKa of strong acids are in practical ...
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1answer
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Finding Gibbs energy at different temperatures just given Gibbs energy at one temperature

How would it be found the Gibbs energy at a certain temperature, if they just give you another Gibbs energy at a temperature? For example: Given $\Delta G = -230 Kcal/mol$ at $773K$ for the reaction $...
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Temperature effects on pKa and pKw

I am an industrial electrician apprentice who needs to learn more about pH-measurements and how the temperature effects the measurement itself (I am in charge of all the pH measurements on the ...
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What would oxygen or nitrogen snow look like?

I was watching a video of what would happen if the earth got kicked out of the solar system and at one point it was mentioned that oxygen and nitrogen snow would form. So would such snow be any ...
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Will there be a temp change in free expansion [closed]

I did a little thought experiment, where I place an infinitely long beaker filled with some gas, which has a moveable piston at the open part. So if I place this beaker in vaccume, there will ...
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What is the difference between fire and warm body? [closed]

A burning body has flames (Candle flame)whereas a hot or warm body (warm utensil or body being hot but doesn’t burn )is just very hot. Keeping hand near a burning body makes you feel hot but not ...
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How to resolve Amine Blush problems of a Epoxy curing Agent without having to change the temperature and moisture of the air?

The formation of Carbamate as a result of the reaction between amine groups of curing agents and H2O/ CO2 leaves the surface of the cured epoxy with some blurry lines and dots. the typical solutions ...
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What is the fundamental difference between temperature and energy? [duplicate]

We know that temperature is proportional to the average kinetic energy of a system. We also know that temperature is not the same as energy because the temperature is intensive while the temperature ...
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The formation of ice crystals on/in frozen food that has been defrosted and then frozen again

I made a mistake. I put my ice cream in the refrigerator instead of the freezer and left it there for a night. I realized my folly the next day. I put it in the freezer. When I took it out, I noticed ...
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Why are some liquids hotter than room temperature gases if liquid and solid molecules move more slowly than gases? [closed]

We learned in school that state change is a matter of molecules moving faster and faster. And we learned "heat em up, speed em up, spread em out". Why then can some liquids have higher ...
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pH scale at various temperatures

I am an electrician apprentice in charge of a large number of pH-sensors/transmitters at a power plant and chemical plant. I do all the pH-instrumentation related maintenance, calibration, adjustments ...
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Why does activation energy depend on temperature? [duplicate]

To me it makes sense that the activation energy $E_\mathrm a$, as given by the Arrhenius equation, doesn't depend on the temperature as the needed energy (potential energy) to start a reaction has ...
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How would one determine the temperature needed such that hydrogen peroxide will start to decompose? [closed]

Hydrogen peroxide decomposes at room temperature and so I was wondering what temperature is sufficient for this decomposition to occur. Can someone explain how we can determine this? (theoretically or ...
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Brittleness of Ice?

I am curious as that I know that various materials can be subjected to fragility from ductile-brittle transition via temperature, where an item is more likely to fracture of shatter such as increase ...
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Thermochemistry: On Units of Enthalpy Change and Implicit Given of Initial Temperature of Calorimeter

I would like to ask two separate questions. But first, so that we are on the same page, the experiment used a constant-pressure calorimeter, and it is a neutralization reaction of 1M of HCl and 1M of ...
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Formulations for wax thermostatic element for effect in alternative temperature range

Wax thermostatic elements are used automobile cooling systems and anti-scald mixing valves to control flow rates or to adjust mixing of flow inputs. These devices operate on the principle of thermal ...
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Does fractionation use enough heat to destroy nutrients in Coconut Oils when seperating the MCT oils?

We have recently been giving MCT (medium-chain triglyceride) oil to our dogs in place of Coconut Oil as from what I understand the majority of the benefits of Coconut Oil comes from the MCT's ...
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How or Why does diesel/kerosene have a much higher 'flash point' but lower auto/self-ignition point than gasoline/petrol?

This is a very common question, but I have yet to find a good theoretical answer to both questions (diesel has higher flash point BUT lower spontaneous ignition temp.)
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Why Does Activation Energy not change with Temperature change

As The Graph Shows; $E_a$ (Activation Energy) = Energy Of transition State(Threshold Energy) $-$ Energy of Reactants. So let This be the graph at Temperature $T_1$, Now say We Increase The Temperature ...
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How can we say that Helium (He) is liquid at “absolute zero”?

According to Wikipedia, Helium can never be solidified at $\pu{1 atm}$ ($\pu{101325 Pa}$) pressure, not even at absolute zero. A minimum of $\pu{25 atm}$ pressure is required to make Helium solid. But ...
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Internal energy for Phase Transitions

Can we justify that "For sublimation of a solid at 1 atm $\Delta U>0$ at low temperature and $\Delta U<0$ at high temperature?" I read several answers and came to know that $U=f(T)$ ...
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Misconception of gas laws [closed]

I face a misconception with gas laws: Boyle’s law, Charles’ law, and Gay-Lussac’s law. This is because each law of these assumes the constancy of one of the three following variables (the pressure, ...
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How does the polarizability of an apolar compound influence properties such as its boiling temperature? [closed]

I have understood that the more polar is a compound, the higher is its boiling temperature. But I would like to know what is the justification for this answer. I am new to chemistry so I would ...
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How to accelerate the evaporation of water at temperature below 5 °C? [closed]

How can we make the water to evaporate at low temperature? Does addition of high evaporating solvents help or decrease in the hydrogen bonding by addition of solute will help? Is there any other ...
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Temperature required for E1 elimination reaction

I wanted to ask what's the temperature required for carrying out elimination reactions? Wherever I read about elimination reactions, they just mention that elimination reactions occur at high ...
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How does pH depend on temperature, when taking into account volume expansion?

Since autodissociation of water is endothermic, increasing the temperature will drive the following equilibrium to the right, which has the effect of increasing $[\ce{H+}]$: $$\ce{H2O <=> H+ + ...
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Does motor oil get more viscous when heated & what is the meaning of the SAE motor oil code?

The motor oil in my 2004 Pontiac Vibe is 5W-30. My (incorrect) understanding of this SAE nomenclature is that 5W means "Viscosity index of 5 in the winter" (or when really cold - like $\pu{-30 ^\...
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Stability of Peroxynitric Acid in cold temperature

I have a question about the stability of Peroxynitric Acid i.e. $\ce{HO2NO2}$ at cold temperature. I know that it becomes stable when temperature decreases, but what is the specific reason for it? I ...
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How can temperature be constant during a reaction? [closed]

So I was reading my textbook about the topic thermodynamics. Here the second paragraph States that the above equation describes the combustion of liquid ethanol at constant temperature and pressure. ...
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Non-conducting substance with a glass transition temperature around 400 to 600 °C?

Am looking for a substance to seel two pieces of ceramic that will have molten plastics flowing between at 300+ °C however silver solder circuit traces inside the device prevent me from going much ...

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