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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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Does freezer burn affect only the cells on the surface of food? [closed]

Suppose i submerge a banana halfway through in a tray with water. Part of the banana is submerged in water, part of it is on the outside. The water and banana in the tray is being put in the freezer ...
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16 views

Physical Chemistry [closed]

In a mile long section of a gas pipeline, the absolute pressure decreases by 51% and the absolute temperature increases by 3 %. The viscosity remains unchanged. The head-loss gradient at the end of ...
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35 views

Why do higher intermolecular forces lead to a higher change in temperature?

We performed an experiment in chemistry where tissue paper soaked in various chemicals was wrapped around the end of a temperature probe. The chemicals with stronger intermolecular forces had a lower ...
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18 views

Specific heat capacity, internal energy and temperature

When metal and water are exposed to the sun for a certain amount of time , the metal will be burning hot from the sun, but the water will not feel as hot because they have different specific heat ...
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21 views

temperature and average kinetic energy

How can temperature and average kinetic energy be the same thing if temp is measured in degrees or Kelvin and KE is measured in joules?
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27 views

How does Boudouard reaction influence the temperature?

I've a question that is giving me a lot of troubles: I'm depositing and gasifying Carbon by varying a flow rate of $\ce{CO}$ and $\ce{CO2}$ and by using the Boudouard reaction ($\ce{2CO -> C + CO}$)...
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5answers
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Why do we still need to know about the Rankine temperature scale?

I am learning process principles in chemical engineering and I was taught various temperature units like Fahrenheit, Celsius, Kelvin, and Rankine. I see the first three being used quite commonly, but ...
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16 views

Up to which temperature and pressure can dendrimers (PAMAM) be stable?

I am preparing PAMAM (poly amido-amine) dendrimer and I want to know up to which temperature and pressure can it be stable?
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1answer
56 views

At what temperature can molecules no longer form?

// hyper simplistic terminology in use for the question - apologies. Molecules are formed by atoms bonding together, and those bonds have an equivalent energy. At what temperature does the thermal ...
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1answer
54 views

Is there a better model than the Kinetic Theory of Gases [closed]

I'm looking for a better relationship between the Kinetic energy of a gas and it's Temperature, and also how they vary with gravity (not altitude, just gravity!). So is there a model better than the ...
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2answers
99 views

Which is the cheapest plastic that retains its structure at 85 °C or higher temperature?

In an academic project, I need to protect some electronics components from heat (around 85 °C). I am searching for both a cheap plastic film and a cheap plastic to be used in a injection molding ...
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2answers
48 views

Process of transferring kinetic energy in regard to photons. [closed]

Now I know that temperature is the average kinetic energy of atoms, molecules and compounds. Photons increase the kinetic energy/temperature of molecules since photons are pure energy. Hence, wouldn't ...
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1answer
28 views

Reaction direction change based on phase of reactants and products

I am curious specifically how the entropy of a reaction will change if the phases of the reactants and products at different conditions change. For instance, a reaction $$\ce{O2(g) + C(s) -> CO2(...
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3answers
425 views

Why are calorimeters often made of materials with low specific heats?

When building calorimeters, a material with a low specific heat is often used (such as Styrofoam, aluminum, etc.). However, why would a material with a low specific heat be preferred? My thought ...
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1answer
37 views

Predicting the temperature of an object using the heat of its surroundings after a certain amount of time?

how would you predict what the temperature of something would be if it spends a certain amount of time exposed to heat from its surroundings? is this possible? ex. what temperature would a hot ...
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1answer
34 views

Can air inside a high temperature (1300C) Kiln cause an explosion?

I saw many kiln designs that lack an opening for hot\pressurized air to come out , or any pressure valve. But when air is heated to such a high temperature (1300C) inside a closed chamber (the kiln), ...
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2answers
126 views

Does hydrogen peroxide - urea become more active when illuminated?

Dentists' tooth whitening systems and consumer kits use gels containing carbamide peroxide, also known as hydrogen peroxide - urea. Dentists use a light activator: (image from Wikipedia). Consumer ...
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1answer
91 views

Will ice be cold or not when formed using pressure? [closed]

We know that ice can be formed either by lowering the temperature of water or by applying more pressure. If we lower the temperature of water the ice so formed will be cool which is obvious. If ice ...
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1answer
54 views

Is there any difference between “autoignition temperature” and “ignition temperature”? [closed]

Is there any difference between the "autoignition temperature" and the "ignition temperature" of a substance?
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1answer
58 views

Can heat capacity at constant volume for a gas decrease as temperature increases? [closed]

I found a function for the $C_V$ of a gas which is being heated under constant volume,but the function shows that the $C_V$ is decreasing. I was wondering if this is possible for any gas since I know ...
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5answers
3k views

Why does the distance between molecules increase when the temperature is raised?

I have learnt that when we heat ice-like substances it changes to water and when I asked my teacher she said that the distance between molecules increases. When I thought about it a bit more a ...
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1answer
66 views

Equilibrium, temperature change, and prediction in constant volume

When it's constant volume, change of $T$ (Kelvin temperature) in a reaction equilibrium system won't change the volume. Let's say we change the temperature from $T$ to $2T$ of this reaction at ...
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2answers
114 views

How does water flows through pipes in cold countries?

This question occurred to me when I looked into the fridge, where the water had frozen due to very low temperatures. If the water freezes due to low temperatures (0 degrees Celsius), then how can it ...
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1answer
23 views

Can the pyrophoric tendencies of a pyrophoric substance be suppressed in a pressurized environment?

It's common knowledge that the pressure of an environment influences many properties of a substance, like the melting point, boiling point, or triple point. Pyrophoric substances ignite spontaneously ...
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22 views

What temperature does oxygen have to be at to bond with carbon monoxide? [duplicate]

I was wondering how I would go about calculating the required temperature of oxygen to bond one oxygen particle with carbon monoxide (CO). I know that it depends on some other factors such as air ...
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0answers
286 views

The effect of temperature increase on sodium hypochlorite concentration in bleach

We are completing an experiment on the effect of temperature increase on sodium hypochlorite concentration in bleach (as calculated using excess iodine and sodium thiosulfate titration) I assume ...
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1answer
61 views

Factors that influence the kinetics of an irreversible exothermic reaction [closed]

I'm trying to understand what are the main factors that influence the reaction rate of an irreversible exothermic reaction. I think these could be the main factors: chemical nature of the reagents ...
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1answer
50 views

Combustion at 298K

Question: (source IITJEE 1992) An aliphatic thiol undergoes combustion at 298K to give carbon dioxide, water and sulfur dioxide. What are the physical states of the products?(solid/liquid/gas) I ...
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2answers
97 views

Can the change in the entropy of the surroundings always be obtained by dividing heat transferred by the temperature at which the transfer occurs?

Consider $\pu{1 mol}$ of an ideal monoatomic gas going through reversible isochoric heating from $\pu{100 K}$ to $\pu{1000 K}$. Calculate $\Delta S_\pu{sys}, \Delta S_\pu{surr}.$ $$\Delta S_\pu{...
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1answer
523 views

How can I interpolate between two densities at different temperatures?

I'm trying to find the temperature of methanol ($\ce{CH3OH}$) when its density is equal to $\pu{780 kg m-3}$. I know that when $T = \pu{30^\circ C}$ the density is equal to $\pu{783 kg m-3}$, and ...
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1answer
44 views

What is the mathematical relation for the change in water density at different temperatures?

I am curious to the relation of the density of water at different temperature and as to also how one would come to an equation that took the temperature of the water and would output it's density? I ...
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1answer
743 views

Changing Temperature of a Galvanic/Voltaic Cell: Should I wait for the electrodes to also change in temperature?

I'm conducting an experiment where I change the temperature of the sulfuric acid in a lead acid storage cell. My one question in controlling the variables is that should I let the electrodes also ...
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2answers
702 views

Why does pH change with temperature? [duplicate]

Why does pH change with temperature? I recently read up on some chemistry notes, and found out that the higher the temperature of distilled water, the lower the pH. Why? Does this apply to other ...
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74 views

dq/T vs. CdT/T for measuring absolute entropy

In principal one could determine absolute entropy for a substance by integrating dq/T from 0K to the temperature of interest. However, I've seen this done using heat capacities, integrating CdT/T ...
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1answer
28 views

Measuring heat effect of reaction

I did an experiment to determine enthalpy change when Zinc is added to Copper(II) sulphate solution. I recorded values and plotted a temperature-time graph to obtain values of the temperature change ...
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1answer
98 views

Change of temperature upon dilution

Consider a concentrated dye solution, say 10µM of Rhodamine 6G in water, which is rapidly diluted down to 10nM in an open container. I'm trying to estimate the (presumably minute) temperature change, ...
3
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1answer
138 views

Am I Using the Correct Number of Significant Figures (Heat Problem)?

The question is: A patient arrives in the emergency room with a burn caused by steam. Calculate the heat, in kilocalories, that is released when $\pu{18.0 g}$ of steam at $\pu{100 °C}$ hits the ...
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2answers
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Are all highly shock sensitive chemicals highly temperature sensitive too?

I found that some highly shock sensitive explosives like lead azide, mercury fulminate have a relatively high auto-ignition temperature. I want to know if it's a general property or not and why so? ...
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1answer
73 views

How to know whether to add latent heat when calculating final temperature?

From the examples in my textbook, it is usually very easy to see whether you need to account for the latent heat when calculating the final temperature. For example, if you add 2 x 13 gram ice blocks ...
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4answers
192 views

Is it possible to freeze water by dissolving a salt?

Theoretically, by dissolving a salt in water the melting point lowers, approximately 1.86 K kg/mol, making it more difficult to freeze water. However, the process of dissolution of certain salts is ...
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433 views

Effect of temperature on vitamin c

We conducted an experiment in a laboratory: titrating tomato juice with an iodine solution. The indication was a freshly prepared solution of starch, which turns bluish black from reddish orange. ...
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1answer
95 views

Is change of pH of water with respect to temperature linear?

Only recently I learned that the pH of water varies with temperature, from about 7.47 at 0 °C to 6.14 at 100 °C. My question is, first, is there a geometric explanation for this, in the sense that ...
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1answer
78 views

Recharge battery using heat

A galvanic cell works by having two electrochemical equilibriums which have a different potential. If you (theoretically) had a galvanic cell with two electrodes which have almost identical ...
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2answers
327 views

Physical Explanation for variation of Gibbs Free Energy with Temperature and Pressure

Reading Atkins Elements of Physical Chemistry right now, and the book says: "At constant pressure and entropy, an increase in temperature ($\Delta T\gt0$) results in a decrease in $G_\mathrm m$ (molar ...
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1answer
268 views

Propylene Glycol as a water main anti-freeze

We are a young student science group looking for solutions to real world problems. We are currently working on ways to keep our city water mains from freezing in the winter. Our team is researching ...
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1answer
181 views

Why does heating transform the aquacomples of slightly acidified cobalt(II) chloride solution to the chlorido complex?

There is a famous demonstration where, if you mix a $\ce{CoCl2}$-solution with the right amount of $\ce{HCl}$ you will end up with the pink $\ce{[Co(H2O)6]^2+}$ complex but when heating it to boiling ...
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1answer
111 views

Thermochromism in PbI2

I noticed while heating some PbI2 powder that it reversibly changes from a yellow to a dark red. However, I was unable to find anything on this thermochromism. There are related cases in TlI and AgI ...
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65 views

Can this happen to superheated water?

Superheated water refers to water that is heating well beyond its usual boiling point under extreme pressure. This cause it to display anomalous property. I noticed that as temperature increases, so ...
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2answers
5k views

Clarification of Kinetic Energy during Phase Change

This website states that: During a change of phase the temperature does not change, but the internal energy does. The internal energy is the sum of the kinetic energy of the molecules and the ...
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45 views

What is negative temperature? [duplicate]

Our teacher (IOC) hinted of something like a "negative temperature". He said that it was "hotter than infinite temperature." What is negative temperature? I'd ask him, but he says that it was ...