Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

For questions about gas pressure, or the effect of pressure in general on chemical species, substances, or reactions.

-1
votes
0answers
21 views

How many liter of air are required?

I have the following question : Producer gas has the following composition in precent of volume : $8.0$%$CO_2$, $23.2$%$CO$, $17.7$%$H_2$, $1.1$%$CH_4$, $50$%$N_2$ How many liters of air (air ...
4
votes
3answers
473 views

Equalization of pressure in heat exchanger

I was solving numericals on Kinetic Theory of Gases when I came across this question Two closed vessel of equal volume contain air at 105 kPa, 300 K and are connected through narrow tube. If one of ...
0
votes
1answer
57 views

Entropy as the driving force for osmosis

How is entropy responsible for osmosis and is movement of solvent possible from its higher concentration to lower concentration? By concentration, I will be referring to the concentration of solvent ...
4
votes
2answers
232 views

Does the rate constant depend on pressure?

I have read in some books that when pressure increases, the number of effective collisions increases. Hence, $k$ depends on pressure. Is it true? If so, then why doesn't $k$ depends on concentration? ...
1
vote
1answer
49 views

Molar mass of a protein from osmotic pressure

The height of a column of liquid that can be supported by a given pressure is inversely proportional to its density. An aqueous solution of $0.010 g$ of a protein in $10 mL$ of water at $20^oC$ ...
2
votes
1answer
85 views

Why does the liquid in an Oralmedic stick flow uphill after I turn it upside-down?

I was experimenting with an Oralmedic stick, which is basically a cotton swab with a hollow stick that has liquid medicine inside, and observed something very unexpected. I followed the usage ...
6
votes
1answer
106 views

Is it true that an evaporating molecule has the same kinetic energy as a molecule in a pot of boiling water?

A molecule on the surface of room-temperature water shoots off the surface of said water, or in other words, it "evaporates." It does so because it gained kinetic energy ...
1
vote
0answers
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?
0
votes
2answers
39 views

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 ...
0
votes
0answers
48 views

Stoichiometry question regarding Kp and amount

$$\ce{2 NH3 (g) -> N2 (g) + 3 H2 (g)}$$ I know the reaction, temperature (600 Celsius), pressure (1 bar), $K_p$ (equilibrium constant regarding pressure)=16,76, and initial $mol_{reactant}$=1 mol. ...
0
votes
1answer
43 views

How to synthesize a material at 2000atmospheres?

I am trying to combine various elments and at high pressure. How to achieve these pressures for a gas and in quantities of at least 1 cubic centimeter.
0
votes
0answers
20 views

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 ...
1
vote
0answers
127 views

What does the osmotic pressure do in an electrolytic soltuion?

I have learnt that in an electrochemical cell, the osmotic pressure in the solution hinders the flow of ions from electrode to the solution, rather some ions may accumulate on the electrode because of ...
0
votes
1answer
44 views

Molecular kinetic interpretation of pressure

Regarding the molecular kinetic interpretation of pressure, we arrive at a point in the $F=\frac{\Delta P}{\Delta t}=\frac{2mvx}{\Delta t}$, that is to say, the force exerted in the shock on the wall ...
0
votes
0answers
23 views

Can pressure increase rusting rates?

Most everyone knows how rust is formed but just to remind you when iron is exposed to oxygen and moisture for extended periods of time. Now if we were to apply much more pressure to the environment ...
0
votes
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), ...
2
votes
0answers
270 views

Conversion of a permeability value from barrer to SI unit

I have done a permeability experiment on LDPE in the presence of air. At $\pu{30^\circ C}$, the permeability was found to be 1.846 barrer. Now I am trying to apply this permeability value to a ...
1
vote
0answers
31 views

Does the way a reaction with gas moles shifts depend on Q or number of moles on either side of the reaction?

Given a container with the reaction $\ce{C2H4{(g)} + HCl{(g)} -> C2H5Cl{(g)}}$, if we inject $\ce{C2H5Cl{(g)}}$ to the container, what will happen? I thought of this in two different ways and got ...
0
votes
1answer
92 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 ...
2
votes
0answers
75 views

How do the pressure acting on the reactants and the initial temperature of the reactants affect the enthalpy of reaction?

In an exothermic reaction that occurs under constant pressure, does the pressure acting on the reactants affect the enthalpy of reaction? Does the initial temperature of the reactants affect the ...
0
votes
1answer
59 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 ...
0
votes
0answers
16 views

PM2.5 - result of compression ignition or Diesel fuel?

When reading about PM2.5 particles, one can see that one of the sources for such particulates is the Diesel engine. I was wondering if it is the Diesel fuel itself or is is the ignition type (i.e. ...
0
votes
0answers
63 views

What causes both components of a binary gas mix to condensate at the same time for a given composition

Okay, so recently I encountered the temperature - mole fraction diagrams for binary vapour-liquid equilibrium. For now, I only consider two-component systems where the components are very similar and ...
0
votes
1answer
24 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 ...
3
votes
2answers
231 views

Le Chatelier’s principle when pressure of gases increased with the same stoichiometric coefficient

$$\ce{C (s) + H2O (g) <=> CO2 (g) + H2 (g)}$$ What will happen to the equilibrium when the pressure of gases is increased? What will happen to the yield of $\ce{H2}$? Since pressure ...
0
votes
3answers
135 views

Pressure dependency in Haber Bosch ammonia synthesis

Haber-Bosch ammonia synthesis reaction: $$\ce{3H2 +N2 -> 2NH3}$$ According to the ideal gas law: $pV=nRT$ where constant volume implies $\displaystyle \frac nV=\frac p{RT}$ Then $\displaystyle ...
0
votes
0answers
52 views

Electrolysis under high pressure

Suppose we submerge a bell-shaped electrolysis chamber, flip it under water to have it filled with water, flip it again (so that the top is closed and the bottom is open), and lower it deep into weak ...
1
vote
2answers
493 views

Why do gases liquify under pressure?

To my understanding, an increase in pressure (of gases in a container) is proportional to an increase in gases' kinetic energy, and hence temperature. However I read that gases liquify under pressure.....
0
votes
0answers
139 views

Filtering water vapour out of air at 0.1 bar options?

I will be conducting an experiment which as a byproduct will release some water vapour in a small pressure chamber. Water vapour can destroy the peristaltic pump and the air needs to be filtered ...
-2
votes
1answer
43 views

Pressure-Volume Formula Question

I have a chemistry homework problem that states the following: $6.2$ L of $N_2$ at $0.74$ bar is mixed with a $15.2$ L sample of $O_2$ at $0.35$ bar. The gaseous mixture is placed in a container of ...
5
votes
1answer
116 views

What happened to this 10 year old unopened plastic bottle?

A colleague of mine found this unopened Aquarius bottle (non-carbonated drink) that was 10 years past its expiration date. The bottle was collapsed inward which would suggest that the pressure in ...
0
votes
0answers
84 views

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 ...
0
votes
1answer
73 views

Mass of oxygen in He+O2 mixture

A sample of $\pu{1.42 g}$ of helium and an unweighted quantity of oxygen gas are mixed in a flask at room temperature. The partial pressure of helium in the flask is $\pu{42.5 torr}$, and partial ...
1
vote
0answers
27 views

Calculating Gas Pressure with Water Vapour

$\pu{4.0 L}$ of oxygen was collected by the displacement of water at $\pu{105.0 kPa}$ pressure and $\pu{30 ^\circ C}$. If the vapour pressure of water at $\pu{30 ^\circ C}$ is $\pu{4.2 kPa}$, ...
-2
votes
1answer
50 views

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 ...
2
votes
2answers
332 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 ...
-2
votes
1answer
54 views

Weight percentage of a component in gaseous mixture

Given a mixture of $\ce{He}$ and $\ce{O2}$ with density $\pu{0.47 g/L}$, temperature $\pu{298.15 K}$ and pressure $\pu{0.948 atm}$. What is the weight % of $\ce{He}$? I get stuck in the formula $$\...
5
votes
2answers
428 views

Calculate ozone layer thickness at a given temperature and pressure [closed]

The ozone concentration in the upper atmosphere averages $\pu{3.0 \times 10^13 molecules per cm3}$ in a region between $15$ and $\pu{35 km}$ high, at an average pressure of $\pu{0.001 atm}$ and ...
1
vote
0answers
118 views

Is brass combustible in high pressure oxygen environment?

Some metals are particularly ignitable in high pressure oxygen environments, like stainless steel and aluminum. Copper and nickel, on the other hand will self-extinguish when ignited. Does anyone know ...
13
votes
2answers
694 views

What is “chemical pressure”?

While reading some publications on solid superconductors, I encountered a term "chemical pressure" a few times, which is usually attributed to the changes of superconducting transition temperature $T_\...
1
vote
2answers
590 views

When two containers at different T and P are kept together, will pressure become same or temperature?

Two containers, kept at different temperatures are connected through a stopcock and two different ideal gases at different pressures are filled inside them. Initially the stopcock is closed. When the ...
2
votes
0answers
1k views

Effect of temperature and pressure on structure of solids

What is the effect of these conditions on the structure of solids? My book has the answer that confuses me. I got nothing about it. Can you please explain? The answer of the book is With the ...
0
votes
0answers
118 views

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 ...
0
votes
0answers
41 views

For a reaction involving a single species what causes a shift in equilibrium?

Consider the following reaction at equilibrium: $$\ce{2 NO + 3 O2 -> 2 NO3}$$ (This is a heterogeneous reaction with all reactants in the gas phase) Let's assume that we increase the volume, ...
14
votes
4answers
4k views

Aside from carbon, what other substances can be made “superhard”?

So diamonds are an allotrope of carbon, that is formed when carbon is put under immense pressure, right? What other elements or compounds can you make into "diamonds", as in more durable, harder ...
0
votes
0answers
130 views

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 ...
1
vote
0answers
98 views

Pressure increase due to the reaction of CaO and HNO3

Currently I'm facing difficulties in determining the pressure increase due to the reaction between $\ce{CaO}$ and $\ce{HNO3}$. To be more specific, we first fill a vessel with $\ce{H2O}$ and $\ce{CaO}$...
1
vote
1answer
207 views

Does temperature change pressure in isochoric system?

Consider the following equilibrium reaction: $$\ce{2 NOCl (g) <=> 2 NO (g) + Cl2 (g)} \qquad \Delta H > 0$$ My textbook has a statement that: If you decrease the temperature when ...
0
votes
0answers
91 views

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 ...
13
votes
3answers
4k views

Why do helium balloons expand in volume as they go higher?

I realize as balloons go higher, the atmospheric pressure decreases, doing less to counteract the force of the gas particles pushing against the inner walls of the balloon. But at the same time, doesn'...