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Change in pressure or volume of molten salt

I am doing a project in which I fill a cylinder with a volume of $636cm^2$ (made of stainless steel) with molten salt: 60% Sodium Nitrate ($NaNO_3$) and 40% Potassium Nitrate($KNO_3$). The container ...
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44 views

Safety concerns - Heating PMMA (acrylic glass) and fluorinated polymers

I have some plastic optical fiber, which consists of a thin core of PMMA (polymethyl methacrylate), covered by a fluorinated polymer. I would like to heat a bundle of these fibers to ~130 degrees, in ...
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53 views

What is the heat required to melt this ice cube?

I am need of help with this question: 18 g is one mole. (a) I guess you meant to 0 degrees C? So, 70.391 x 20 = 1408 J (b) 6.01 kJ (c) 180 g is 10 moles. It would take about 15kJ to cool all of ...
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1answer
69 views

How do you calculate the total heat capacity of a reaction

I need help with this one homework question: I am combining $100\,\text{mL}$ of $0.5~\text{M}~\ce{HCl}$ and $100~\text{mL}$ of $0.5~\text{M}~\ce{NaOH}$ to obtain $200~\text{mL}$ of ...
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1answer
44 views

determine vapor pressure of mixture

I am looking to calculate the minimum heat needed to create vapor from a specific mixture. I have a mixture of 60% $\ce{C3H8O3}$ (glycerine) and 40% $\ce{C3H8O2} $ (propylene glycol, ...
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1answer
67 views

Why does glass shatter when heat is applied to it?

When I poured hot tea into a cup, the cup shattered after about three seconds. The cup was made of glass. It was pretty thin. How did the glass and the tea react in terms of chemicals. This is a bit ...
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1answer
43 views

Finding the final temperature

If $125$ Calories of heat is applied to $60.0\text{g}$ piece of copper at $21.0^\circ\text{C}$, what will the final temperature be? The specific head of copper is $0.0920 \text{ cal/gC}$. All I have ...
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1answer
48 views

Baking Soda + Oil at high temps

My mom while making Potato chips put some Baking Soda in Oil with it. Just curious to know, it was first time Baking Soda in Oil at that high temperature. Is it safe to eat? Answer ASAP before my ...
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1answer
77 views

Difficult calorimetry problems?

I figured out how to do all of the calorimetry problems except for the last few, which are the hardest of the bunch. Assume there is no heat exchanged with the environment. A. 1250 kJ of energy are ...
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1answer
43 views

general chemistry 2 heat of vaporization

Question 1. A 20.0 gram sample of n-propanal requires 9.748 kJ of heat to change from the liquid to the gas phase at its boiling point temperature. Show using these measurements a calculation of the ...
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1answer
216 views

Heat Produced when Mg is reacted with HCL

Calculate the heat produced when a strip of $\ce{Mg}$ metal with a mass of $0.0801$ gram is reacted with $50.0$ml of $1.0M$ $\ce{HCl}$ to raise the temperature of water to $7.6^\circ C$ (change in ...
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70 views

How well (or poorly) does natural leather insulate?

What is the general thermal conductivity of animal skin leather? I understand there are many different animal's skins (cow, sheep, buffalo, deer, pig), but in general, does natural leather insulate ...
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82 views

Is tea powder better dissolved when put in hot water?

I usually make tea by adding two spoons of tea powder to water at room temp. and start to heat it. My friend said it will be better to add the powder once the water starts boiling. She said that it ...
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0answers
21 views

Can you heat water with chemical additives? Would it remain safe to drink? [duplicate]

I've been wondering, is there some chemical that reacts with water, causes heat but isn't toxic?
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1answer
146 views

Determine final temperature from acid base neutralization equation and moles

50 ml of 0.2 M solution of HCl is mixed with 75 ml of 0.2 M solution of NaOH in a constant pressure calorimeter. The acid base neutralization which occurs can written as: $\ce{H+_{(aq)} + OH-_{(aq)} ...
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1answer
131 views

Is it customary to express heat loss as a negative number?

In my chemistry class, we had a problem akin to the following: If an object with mass bla and specific heat bla is placed into a bla g calorimeter with an initial temperature of bla and a specific ...
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1answer
48 views

How do I find the thermal effect of this reaction?

I have graphite turning into diamond.I need to find the thermal effect of this reaction.How would one write that?I'm not sure how to proceed here.The teacher told us to use oxygen?
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1answer
159 views

How much heat is required to dehydrate a hydrate?

If I have a hydrate, such as copper (II) sulfate pentahydrate, $\ce{CuSO_4 \cdot 5H_2O}$, what is the amount of heat to required to dehydrate it? I assume that it is equal to or greater than the ...
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2answers
180 views

Why is water evaporation not more commonly used to cool buildings [closed]

Water has a very high heat of vaporization (2260 kJ per kg). Why not just gradually sprinkle water on your roof to keep the building cool in opposed to using air conditioners? It wouldn't take much ...
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2answers
81 views

What is known about liquid carbon?

The wiki tells me that if you heat carbon at atmospheric pressure it eventually turns directly into a gas without being liquid first. At what pressure can you make liquid carbon? Has anyone actually ...
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0answers
70 views

energy efficiency, transformation from chemical to thermal energy, for district heating plants

If I have a system in which I introduce 100e.u.F (energy units) derived from chemical energy (i.e. fuel) and generate thermal energy to heat water what are e.u. absorbed by water? I.e. the efficiency ...
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1answer
67 views

What is the heat energy required to perform electrolysis equivalent?

The question may be off-topic here. If my concept is flawed, please poke me in the rib (+: Sources on the internet indicate a minimum 1.2Volts is adequate for electrolysis of water; nominally 6V. ...
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1answer
635 views

What is the effect of adding salt to ice?

What will happen to the melting point temperature of ice if some common salt is added to it? How to justfy the answer?
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2answers
380 views

Can you heat water with additives?

I have been curious about this question for a while. If you want to warm up a large amount of water, is it feasible to do this by adding a substance that has an exothermic reaction with the water? ...
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3answers
2k views

How do I chill water without a refrigerator?

How can we chill water in a plastic bottle without a freezer or refrigerator? Scenario: I'm in the office and I have two plastic bottles of water (brought from home). I'm in the office for 3 to 4 ...
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1answer
149 views

Specific latent heat of fusion of a noble gas

Could someone explain to me where the additional energy goes when applied to an object in the state of melting (such as water) so that the temperature of the object does not increase, and could ...
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2answers
121 views

Egg-Detection in Pastries: An Analysis in Heat-Alterated Molecule Identification

I would like to know if anybody here knows of a method to detect the presence of ovalbumin--or any unique, egg-related molecule, in a baked good. Here I am anticipating that the "unique egg-related ...
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2answers
183 views

Better understanding the pyrolysis reaction

I'm no chemist, but much of my work revolves around biochar. I've always understood it with the following rough approximation: $$CH_2O + heat \rightarrow BC + H_2 + CO + CH_4 + HC's$$ where the ...
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1answer
483 views

Is the activation barrier of a reaction related to the free energy or heat of formation of its reactants?

The energy barrier for activation appears in the derivation of a bimolecular reaction through collision or transition state theory, but it seems that from looking at diagram such as this one it seems ...
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1answer
63 views

Why do we need to incubate this system for 18 hours at 60 degrees Celsius?

I am conducting a bio-chemistry related experiment and I have been unable to understand a step which is commonly performed. The procedure that is confusing me is outlined in the supporting ...
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1answer
39 views

What determines a substance's energy of activation with air?

Ice will melt when heat is applied; paper will catch fire. In trying to figure out why — what the difference is between things that melt and things that catch — I found "Burn, Char, Melt" by Roberto ...
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1answer
2k views

Enthalpy Calculations, Heat of Formation/Combustion

I just don't understand how to do these and would really appreciate your help. 1) Ammonium dichromate decomposes in a reaction when heated. Calculate the heat transferred for the decomposition of ...
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1answer
2k views

Why does a substance with an endothermic heat of solution dissolve?

How does a substance with an endothermic heat of solution dissolve?
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227 views

Which materials/compounds expand in response to cold temperatures?

Which materials or compounds expand in response to cold temperatures? This material or compound should expand at a slow (but constant rate), from about 0-20 months when in the following temperature ...