Questions tagged [pressure]
For questions about gas pressure, or the effect of pressure in general on chemical species, substances, or reactions.
309 questions
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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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Find the boiling point of a compound given a pressure
I need to find the boiling point (in degrees centigrade) of ethanol on a day when the atmospheric pressure is $780\text{ torr}$.
I know that the molar mass of ethanol is $46.07\text{ g/mol}$ but I ...
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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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Understanding Avogrado's hypothesis
I have read that gases under identical conditions of temperature, pressure, and volume contain the same number of molecules, but every gas has different types of atoms so their force of attraction is ...
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Vacuum at different altitude
I have tried to find this searching the internet and I am not sure if I understand it. I want to turn water from solid to gas without going into the liquid phase - Sublimation.
The altitude above sea ...
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Pressure increase on rate of reaction
For reactions involving gases, an increase in pressure is no different from increasing the concentration of reactant particles, thus increasing the rate of reaction. But for reactions involves ...
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How high in (mmH2O) is the column of water in the tube?
A long glass tube, sealed at one end, has an inner diameter of 23.4 mm. The tube is filled with water and inverted into a pail of water. If the atmospheric pressure is 735 mmHg, how high (in mmH2O) is ...
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If a pocket of nitrogen gas is pumped in at the bottom intake of a padded tank will the pocket of gas bubble up?
I have a nitrogen gas padded tank (tank 1) which is filled from the bottom of the tank. Tank has a set point of 30 psi which adjusted as tank level changes. Also at the inlet is an additional pipe ...
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Osmotic pressure for non-electrical neutral region of a solution
For calculation of the osmotic pressure, we can use Van't Hoff equation as below:
π=CRT
If we put the solution in an electrical field, the cations and anions move towards negative and positive pols, ...
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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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Osmotic Pressure of Aqueous Solution
The osmotic pressure of an aqueous solution at $25$ Celsius is $92.0$ $kPa$. Calculate the boiling point
of the solution. (Assume that the density of the solution is $1.0$ $g/mL$, ignore the mass of ...
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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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Finding rate constant from a change in pressure experiment
I measured the change in pressure for the decomposition of hydrogen peroxide in the presence of a manganese(IV) oxide catalyst at 5 different temperatures:
$$\ce{2 H2O2 (l) ->[MnO2 (s)] O2 (g) + 2 ...
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Volume of compressed helium gas needed for FE test on ball valves
I'm currently doing a case study to find out the exact volume of helium gas required for FE tests on ball valves regards to the valves' volume and pressure class and the number of helium tanks needed ...
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Can I mix pressures and concentrations when finding equilibrium constant? [duplicate]
In order to find the equilibrium constant (or reaction quotient) I know I can find the value as the products over reactants raised to coefficient exponents. But, in all of the problems I have had to ...
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Ratio of rates of diffusion of gases
I stumbled upon a question, A mixture of 50 mL of Hydrogen gas and 50mL of Oxygen gas is allowed to effuse through an effusimeter. After some time it is observed that the residual gas occupies 90mL. ...
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How does pressure influence the dehydration of salts?
It's well known that the boiling point of a substance increases with pressure. I was wondering if something similar happens with hydrated salts and the temperature at which they dehydrate.
I mean, if ...
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how to Find $P_{tot}$ Given that $K_p = 28.5$ and the partial pressure at equilibrium
I have the equilibrium equation :
$4KO_2{_{(s)}} + 2CO_2{_{(g)}} \ce{<=>} 2K_2CO_3{_{(s)}} + 3O_2{_{(g)}}~~k_p = 28.5 ~at ~25C$.
Given that The partial Pressure of $CO_2$ is $0.191~atm$ at ...
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Finding the partial pressure
So I saw this problem but can't seem to figure out how to get the answer. I got a test tomorrow lol.
41) $\ce{SO2Cl2}$ decomposes in the gas phase by the following reaction:
$$\ce{SO2Cl2 -> SO2(g)...
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What exactly causes equilibrium to shift when pressure is decreased? [duplicate]
Take the reaction:
$$\ce{N2(g) + 3 H2(g) <=> 2 NH3(g)}$$
If pressure is decreased, equilibrium shifts to the left because it has more moles. I understand the basics of why this is, i.e. due to ...
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Pressure dependent rate coefficient
I am trying to study how the pressure will affect the formation of ozone at around 5 bar. So, I am looking for a simple relation between the reaction rate coefficient and the pressure to use it in my ...
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Find the Total Pressure When the Faucet is Released
Two chambers are connected as shown in the figure. The total pressure of the first chamber that contains Ar and He gas is 98.4 atm. If the faucet is released, find the total pressure. (There's 1 mol ...
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Gas concentrations along the gradient from sea level to deep-sea
Studying scuba diving-related phenomenas I thought about how to estimate gases concentration down the sea.
Of course, solubility of gases at, for example, $5$ atm of pressure, can be estimated with ...
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Can every liquid pure substance be compressed to solid?
Apart form the fact that liquid are often misleadingly considered incompressible,
fact that I recently find out to be true only as an approximation in specific circumstances.
I was curious to know if ...
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Why doesn't a temperature and pressure gradient exist in a container of real gas?
In the Kinetic theory of gases, it is assumed that there are no intermolecular forces between the atoms/molecules. But real gases, have intermolecular attractive and repulsive forces.
Suppose a ...
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Is OH + CO → CO2 + H an elementary reaction?
Is
$$\rm OH + CO \longrightarrow CO_2 + H$$
an elementary reaction? How could I tell?
I could break the reaction into
$$\rm OH\ (+ M) \longrightarrow O + H\ (+ M)$$
$$\rm CO + O \longrightarrow ...
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How does Le Chatelier's principle apply to a fuel tank full of hydrogen?
A nano-tube packed fuel tank is full of Hydrogen, and there is a steady pressure of Hydrogen in the tank. While hydrogen gas is being removed from the fuel tank to power the car, the pressure in the ...
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Is vapour pressure of a liquid solution constant at a given temperature, no matter the size of closed container and amount of liquid taken?
Does vapour pressure of a liquid solution depend on the size of the closed container, the amount of solution taken, given that, the temperature is kept constant? Or will it change if some extra gas is ...
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Osmotic pressure of a solution of a protein?
A small protein molecule, code-named "sloth", has a MM of $\mathrm{1.50 x 10^4}$ g/mol. What is the osmotic pressure exerted at $\mathrm{24.0^oC}$ by 25.0 mL of an aqueous solution that contains $\...
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Ice under very high pressure phase transitions [duplicate]
If you put a piece of ice into a very high pressure chamber and increase the pressure, I can understand how the ice turns to a water state. But what happens after that? Does the pressure push the ...
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What's the effect of Pressure change in Chemical Equilibrium if any reactant or product is Solid or Liquid?
I am studying Le Chatelier's Principle of Chemical Equilibrium. I am trying to solve a problem involving the effect of a pressure change on a chemical equilibrium.
I know that if a reversible reaction ...
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If I hard boil eggs in a pressure cooker, will I get the same results regardless of altitude?
This seems like it should be obvious but for some reason (my chemistry is very rusty) I'm having a hard time articulating why the hardboiled egg recipe in an instant pot should yield the same results ...
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Can work be done on a body when temperature and pressure are changed without changing its volume?
Can work be done on a gaseous system when temperature and pressure are changed without changing it's volume?
In chemistry the formula of work is always $p\,\mathrm dV,$ whereas we can also do work on ...
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Can you make n-Hexane a supercritical fluid? [closed]
When making aerogel using supercritical fluids the liquid in the gel is replaced by a gas. Can this be achieved using n-Hexane as the supercritical fluid? What would the resulting gas be? Would it be ...
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Why is the relationship between vapour pressure and boiling point of water non-linear?
From my rudimentary understanding of chemistry, pressure should be directly proportional to temperature for a constant mass of gas under the same volume (Charles’s law).
However, in the diagram above,...
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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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Why is there a limit to the amount of water vapor in the air even though the atmosphere is so vast? [closed]
I have read that temperature and pressure dictate how much water vapor can exist in the air.
Air is a mixture, so shouldn’t the addition of water vapor just add to the mixture regardless the ...
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What would happen if I increase the pressure and temperature of a gas present in a container
Assume the gas to be a real gas and the container to be made of diamond or anything stronger than that. Take the amount of gas to be 2mL and the pressure is increased with the help of strongest ...
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Vapor Pressure of reaction mass undergoing an exothermic reaction
A vessel containing a reaction mass under going an exothermic reaction is under vacuum, with temperature and pressure constant. When the source of vacuum is closed, the reactor begins to increase ...
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Doesn't adding an inert gas at constant volume increase the partial pressures?
When you add an inert gas to a container of constant volume full of gases, you are basically shoving the inert gas into the container and increasing the pressure inside the container, so the partial ...
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Effects on pressure on reverse electrolysis
I am interested in the effects on pressure of the following reaction.
$$\ce{O2 + 4H+ + 4e- → 2H2O}$$
I have been trying to find data on this for a while, and I am sure that the information exists, but ...
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If I make CO2 by exposing CaCO3 to HCl, how much of it would be dissolved in the water [closed]
For an experiment we're trying to measure the amount of gas produced in this reaction. But we always find less gas then expected, then a colleague told me that it could be because some of the CO2 ...
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Calculating percentage of Zn in a coin
Question:
An old coin found in an ancient temple is composed of zinc coated with copper. In an experiment to find the percent zinc in the coin, a student determined the weight of the coin to be 3.0 g. ...
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Ideal Gas Equation Extreme Case [closed]
I have recently learned about the Ideal Gas Equation and I have this doubt.....suppose I am in a closed container filled with a gas of fixed volume and definite amount of moles. I am assuming myself ...
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Is there more efficient reaction for generating hydrogen rather than HCl+Al [closed]
I want to generate hydrogen to acquire known pressure inside of an object.
I have calculated required mole number for hydrogen using the ideal gas equation by giving wanted pressure, volume and ...
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Is vapour pressure a surface phenomenon?
As a fact, I know that vapour pressure doesn't depend on surface area.
Does this imply it is not a surface phenomenon also?
It shouldn't be as then it would depend on surface area of molecules and ...
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Latent Heat, Vapor pressure and Equilibrium [duplicate]
So after reading about this topic i wanted to share what i learned and i wanted you guys to tell me if what i am writting is correct:
A pressure vessel has propane inside and it is pressurized. The ...
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Why does increase in pressure cause a increase in boiling point [closed]
When we increase the atomospheric pressure pressure above the solution , the boiling point of a solution increases. Why does this happen?
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How can equilibrium lie to one side ? Surely it’s not at equilibrium anymore? [closed]
Surely they’re not at equilibrium any more?
I understand that a favourable condition can make a reaction in one direction go faster, but then surely either the forward or backward reaction is faster ...
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How can pressure build up in an equimolar gaseous reaction? [closed]
To make the question concrete, if you conduct a reaction like $\ce{H2 + Cl2 -> 2HCl}$ in a stoppered test tube, the stopper will aggressively pop off (or the glass will shatter) despite the fact ...
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