i am looking for a chemical compound that has a boiling or condensation temperature between 10C and 50C at standard pressure and is not one prohibited for discussion in the Physics Forum or any online chemical forums. something that is organic and not very toxic is preferred. it should be...
Hey guys, I'll try to be as direct as possible. So for school i'm doing an experiment at home trying to find out if the diameter of a pot affects the time it takes to boil water inside the pot as it says in the title. I had three different pots with three different diameters. I got half a liter...
I boil water in a tea kettle. When it's starting to boil there are pinging sounds. These grow louder until there is some sort of phase transition and they quiet down. That's about when the tea kettle starts to whistle. What's going on?
in solid form (the salt that is)?
I had to try to answer this question for my 14 y/o cousin and think I may have messed it up. Good thing she knows I suck at science and to ASK HER TEACHER next time! :smile:
Anyways, it got me curious. . .I first thought of just reversing the process. Since...
Hello,
Could someone please help me understand how to approximate how long it will take for liquid nitrogen in a room temperature container to completely evaporate.
Here's the scenario:
I have a metal container (41x13x15") filled with 5.5" of liquid nitrogen (just released from a Dewar ~ 320F)...
High School Physics Lab: Take 200mL of water (Room temp) and place it in a microwave on high for 60 seconds. Calculate the Energy transferred to the water by the microwave.
Pretty easy:
Step 1: Heat of Temp Change : Q= mC∆T where m=200mL
Step 2: Add Heat due to phase change: Q=mL where m=...
Every morning I boil two eggs for ten minutes. My gas canister emptied faster than I thought it would. Now I had noticed that most of the air heated by the gas never touches the pot. I had another burner with half the diameter of the one I had been using. That means 1/4 the circumference...
I am looking for a good working fluid whose boiling point is in the range of 150-180 F for a waste heat recovery system. The fluid should be minimally flammable, preferably nontoxic, and low in environmental impact. Does anyone know of any working fluids that match this description?
I think the water in the bowl of water will boil first because the glass won't conduct the heat instantaneously, and hence the water in the glass will boil after the water in the bowl. Is this correct?
I am guessing this is a trick question and the water in both boil at the same time, but I...
Water (any liquid) in a closed container boils when the vapor pressure of water (a property that depends on its temperature) equals the surrounding pressure. The vapor pressure of water at 60℃ is about ##1.99\times10^{4}## which is roughly 150 mm Hg.This principle is so simple, and yet, it is...
Fuel oil like heavy fuel oil consists of multiple different Carbon and Hydrogen molecule strains. This means that there are a multiple of different boiling points with in the same oil. Cavitation in pumps and valves happen when due to the acceleration of the fluid the pressure drop causing the...
answer is 78oCdelta G = delta H - T delta S
-235,310- (-277,690) = -38.56e3- T (282.59-160.70)
T = -664K
I am not sure if my concept is correct. May anyone help a little bit on that please?
thank you
Table
boiling point (°C)
melting point (°C)
TiF4
284
N/A
TiCl4
-24
136.5
TiBr4
38
233.5
TiI4
155
377
The solution says that TiF4 is an ionic compound, while TiCl4, TiBr4, and TiI4 are covalent compounds. How would I determine this from the problem without prior...
Why does the isomer C-C-C-N have the highest boiling point, rather than CC(N)C (where the N is attached to the second carbon)?
Isn't N able to form 3 H-bonds in both cases? Thanks.
If you bring a pot of water to boil, you will notice that the bubbles form on the bottom surface of the pot. This seems to make sense intuitively as this is the hottest surface, so this would be where the boiling action starts.
When I was in school during a thermo lab we pulled a vacuum in a...
Recently I have been boiling tap water, for about 30 minutes, everyday for drinking water. The reason I do it is because I don't like the taste of chlorimines and chlorine and this is the only way I know to get rid of them without also losing minerals. It works great, and in fact, the water...
Is it the lower the boiling point the better? As room pressure and temperature already can change the phase without working at vacuum?
And the higher critical point means it is hard to reach super critical phase?
But there is transcritical CO2 cycle, which the critical point is so low, and...
The professor posted a take-home problem for us to solve for extra credit.
Extra credit problem:
Using nothing but pen, paper and a ham, calculate the boiling point of 1:1:1 solution of benzene, pentane, and ethylene in a pressurized tank filled with neon at 6 atm pressure. The Answer must be...
Calculate the boiling temperature of methanol at 60 atm knowing that Tc = 513K, Pc = 78 atm and the acentricity is 0.555.
I would like you to help me start the exercise.
I thought about using the Pitzer Correlation to be able to calculate the fugacity coefficient, but I don't have the...
Two points that i am not getting, please help me understanding them:1-Why is it that a solution of a material (say sugar) is water will raise the boiling point of the solution ?2-Why does the the boiling point of the solution depends on the number of moles (of the material (eg sugar, salt ...))...
I have heard something very strange recently, it is if you boil water too many times then it becomes poisonous? I really doubt this would happen because what boiled water is pure water at a different temperature.
I have heard something very strange recently, it is if you boil water too many times then it becomes poisonous? I really doubt this would happen because what boiled water is pure water at a different temperature.
Two points that i am not getting, please help me understanding them:1-Why is it that a solution of a material (say sugar) is water will raise the boiling point of the solution ?2-Why does the the boiling point of the solution depends on the number of moles (of the material (eg sugar, salt ...))...
I am wondering about the impact of the hydro static pressure of a fluid on its boiling point.
The simplest real world example scenario I can think of is the rate/onset of cavitation at a large depth vs a shallow depth.
As we increase the submarine propellor speed to a speed where the adjacent...
I understand that liquid argon is constantly boiling when it's in contact with the air in the lab, but I want to increase that boil off rate. Because of that, I got myself a high powered resistor (1 ohm, 100 W) and got the highest current power supply I had (5A). When I supply about 5 V and 5 A...
This probably occurs with salt too but let's concentrate on xylitol: you heat water till it boils, put the hot water in a cup and add a tsp of xylitol. It boils again violently for a couple of seconds. The high school explanation is that the boiling point of the water is lowered. I'd like to...
Does temperature increase when water is boiling at 100C in a closed system? I am picturing a scenario where I am boiling water in a pot to make pasta. However, I decide to close the pot as the water is still boiling. By doing this I am sealing away the system of study from the environment. Thus...
Hi everyone,
I have been mulling over the relationship between pressure and boiling for some time, and I am still slightly confused. I shall attempt to provide an overview of my current understanding in the hope that I can get some corrections/clarification on my current conceptual...
When water converts to steam while boiling a vapour dome can be formed, what is the degree of freedom inside this vapour dome and on the saturated points?
Some polymeric intermetallic pentaflouride have boiling points around 200+°C. Can an LFTR be build like a low pressure BWR while maintaining comparable efficiency under lower operating temperature?
I am trying to calculate the increase in pressure caused by liquid nitrogen when it changes from liquid to vapor within a closed, constant volume at atmospheric pressure. How can this be done? Do I need to include the heat of vaporization?
Homework Statement
Explain the following order of the boiling point (° C)
HF (19.5)> HCl (-85.1) <HBr (-66.8) <HI (-35.4)
b) Explain the following order of connection distance (pm):
HF (92) <HCl (127) <HBr (141) <HI (161)
Homework Equations
xxx
The Attempt at a Solution
a) HF does hydrogen...
Hello,
I am encountering some confusion with the relation between the latent heat of vaporization and the temperature of a substance. I understand both the latent heat and the entropy change of vaporization are dependent on the temperature, assuming the pressure is held constant. However given...
When you heat a pot of water why wouldn't the water temp decrease slightly when it starts boiling? Isnt boiling a type of evaporation? In evaporation the molecules near surface have enough KE to escape into the gas phase, which then lowers the T of the remaining liquid. That is how sweating...
Homework Statement
Why is the boiling point of 2-propanol lower than 1-propanol?
The Attempt at a Solution
Is this right?
Because 2-propanol has its hydroxyl group in the middle of the atom, the electrons are all moving to the centre of the atom as opposed to 1-propanol, which has the...
After carrying out reflux and distillation to produce ethyl ethanoate (ethyl acetate) I measured the boiling point and I got 71 degrees Celsius whereas the true value is 77.1 degrees Celsius. Impurities increase the Boiling point (BP) as well as concentration. However my calculates BP is lower...
When we fill a dewar or any other container with liquid argon (or liquid nitrogen), if I am correct, it sizzles because it is boiling. However, after we leave it inside for a few minutes, it stops. Does this happen because when you first pour it inside, the environment is of the liquid is much...
In the normal conditions (sea level) water evaporates at 100 C.
In thermodynamics, we say: the amount of energy Q, can raise temperature of the liquid by the formula Q1=cm(t2-t1); when the liquid reaches the boiling point (100 C), we write Q2=Lm.
Q2 is entirely spent on changing liquid state...
Hi everyone, just wanted to know how does a soluble, volatile impurity affect the boiling point of a liquid? I know it depends on the difference between the boiling points of the liquid and the impurity, but I'm afraid i still didn't get the point.
Thanks
I am looking for a graduate level textbook that would sufficiently describe the two phase flow characteristics during flow boiling. What textbook could I use to explore this topic?
Is a graduate level forced convection going to cover two phase flow?
Homework Statement
This is more like a design problem, I'm to evaporate water at 20°C and 2000 psi(Tsat=335.472°C), I have the heat flux the water is going to absorb during heating, and If that flux remains constant during all the length then, how can I find the surface temperature for the...
Things I have thought of till now:
Acetonitrile with HI additive
Acetonitrile with DMSO additive
The problem with the first would be that HI is in an around 55% aqueous solution and water doesn't play well with the perovskite. Meanwhile, the second might end up needing enough DMSO to...
Hello!
This question is not about a particular homework exercise, or any exercise, but rather an astonishing real life fact, which I just experienced, and, as I am still on my way to becoming educated in science, I would like to ask for your help on how to explain this phenomena.
I had a...
Imagine some giant glass(or other material) dome placed on top of some ocean or lake. Then pump some air out of this dome, until the water level rises a few meters under the dome.
Place another dome below the first dome, and repeat the process, resulting in a little less pressure in the second...
I just had a lab, and the results really aren't adding up to what i expected. And this is specifically about simple distillation, not fractional distillation.
Lets say i have a solution of two liquids, one's boiling point is 90°C and the other is 110°C, a 20°C difference which is pretty close...
Hello,
I have a question for you guys and gals. I am working on a Desalination project and am ironing out questions about efficiency. What would be the most efficient temperature to evaporate water? 50, 100, 110 degrees? Does it make a difference, or is the energy required to evaporate a fixed...
Hello everyone
in a synthesis, they mixed oleylamine with a boiling solution of toluene for 2hours
they didn't mention if it's with reflux or not !
i don't know if it doesn't represent any harmful consequence even in fume hood