Physical and chemical laws describing the properties and behavior of gases.

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Liquification of gas to liquid at critical temperature

The gas that liquifies first, when cooled from 500K to its critical temperature given in parenthesis is a) $\ce{CO2}$ (304.1 K) b) $\ce{NH3}$ (405.5 K) c) $\ce{O2}$ (154.3 K) d) $\ce{N2}$ (126.0 ...
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Volume occupied by real gases

Molecules of an ideal gas are assumed to have zero volume, the volume available to them for motion is always the same as the volume of the container. In contrast, the molecules of a real gas have ...
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How do we compute the mole fraction of an ideal gas in a stream blended by mass flow controllers? For a non-ideal gas?

Consider a gas blending system consisting of two mass flow controllers, A and B, set to control flow to $f_A$ and $f_B$, respectively. Consider that flow controller A is metering the pure gas of ...
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39 views

Non-Ideal Gas Behavior

I obtained measurements of temperature and pressure at various temperatures ($-10, 0, 20, \text{ and } 50^\circ \mathrm{C}$) and plotted them on a graph. Projecting backwards, the best-fit line ...
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19 views

determine density of oxygen gas using modified ideal gas equation

I am trying to determine the density of a gas (oxygen). As the gas is a compressible fluid a modified version of the ideal gas equation is required. I have been given the following equation and I am ...
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Can Helium be scented? [closed]

Is it possible to have Helium scented? If so, can it be done in large quantities? I'm interested in using a peppermint type scent.
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combustion of natural gas and oxygen overall molar and volume ratio

I am trying to calculate molar ratio between natural gas and oxygen for the complete combustion reaction of all the fuels components. so I want to work out how much oxygen I need to natural gas. The ...
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17 views

10dm3 of N2 and a gas X at the same temperature contains the same number of molecules. The other gas is?

According to the solution on my book, the correct answer is CO as the molar mass of both N2 and CO is the same. However, doesn't Avogadro's law state that equal volumes of all gases at the same ...
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36 views

Resultant temperature of mixture

**Question: ** There are 2 flasks of equal volume, connected by a narrow tube of negligible volume, filled with nitrogen gas. When both are immersed in boiling water, the gas pressure inside the ...
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34 views

molar mass using gas law

home / study / questions and answers / science / chemistry / did I do this right the answer does not seem right … A gas has a volume of $255\ \mathrm{mL}$, a pressure of $733\ \mathrm{mmHg}$, a ...
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24 views

Does turning propan butan gas tank upside down help to use gas remainings?

Some think that when gas (propan-butan mixture for cooking) in a gas tank is almost used (only remainings are left inside and the flame is hardly noticeable) and you turn it upside down it will ...
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19 views

using the volume percentage and constant pressure to calculate the molar mass of air

With the purpose of verifying (calculating) the average molar mass of air $M$ which is almost equal to $29$ $g/mol$, we shall use the percentage of moles of various air constituents. Let's assume we ...
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71 views

Free energy of an ideal gas

I want to calculate the Gibbs free energy for an ideal monoatomic gas, i.e. $$U=\frac32nRT.$$ Free energy is defined as $G(T,p)=H-TS$ and using the definition of enthalpy $$G(T,p)=U+pV-TS=U+nRT-TS.$$ ...
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41 views

What does gases at constant pressure mean?

My teacher told me that if we keep some weight on a piston containing 2 different gases,both gases will be at constant pressure and hence the volume occupied by each gas will be proportional to number ...
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Real Gas - Van der Waal's Equation

The Van der Waal's Equation for a real gas is: $$RT=(P+\frac{a}{V_\mathrm{m}^2})(V_\mathrm{m}-b)$$ We have understood this formula by saying that $a$ is the term which is for force of attraction ...
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1answer
31 views

How to find the molar volume of 1 gas in a 2 gas system using PV_m=ZRT?

Using $PV_m=ZRT$, would I need to use the total pressure of the system or the partial pressure of the gas I am interested in to work out the molar volume?
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47 views

Can gaseous hydrogen and gaseous oxygen be compressed without reaction?

I'm looking into building a clean Bunsen-style burner (or rocket engine - I haven't decided yet). I will be using electrolysis to extract hydrogen and oxygen from water, but the apparatus I am ...
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50 views

Why is partial pressure proportional to mole fraction in Henry's law?

According to Henry's law of partial pressure, partial pressure of a gas above a solution is directly proportional to the mole fraction of the gas in the solution. But my question is: If the mole ...
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1answer
65 views

Why does CO2 lowers the pH of water below 7?

Ok so I understand that having a pH below 7 is considered to be acidic and I also understand that part of the definition of an acid is that it gives off H+ when dissolved in water(even though not all ...
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77 views

How to determine the mole fraction of the liquid phase from a given mole fraction of the vapour phase for a benzene/toluene mixture?

A quantity of benzene, $\ce{C6H6}$, and toluene, $\ce{C6H5CH3}$, is placed in a $1~\mathrm{L}$ evacuated vessel at $25~\mathrm{^\circ C}$. At equilibrium, a small volume of liquid is visible at the ...
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47 views

What is the pressure belonging to in Boyle's Law?

Just a hour ago, I was reading the great and highly interesting, Boyle's Law. In my textbook, there is given Boyle's Law and leaving some pages, there is stated Dalton's Law of Partial Pressure. ...
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195 views

How to calculate air tank capacity from tank displacement, tank fill (gauge) pressure, and specific type of gas?

I am trying to calculate the amount of a specific compressed gas that will fit in an air tank of specific displacement, at a specific pressure. This is in reference to compressed air guns. The inputs ...
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How does one derive the average velocity of an ideal gas molecule?

I found that if a velocity of a gas follows the Maxwell-Boltzmann distribution, the mean velocity is given by $$\langle v \rangle = \sqrt{\frac{8RT}{\pi M}}$$ where $R$ is the gas constant, $T$ is ...
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Does an increase of area lead to more collisons in a confined jar of gas?

I'm reading a lecture by Richard Feynman in which he is talking about the behaviour of gas molecules/atoms within a confined vessel. The confined vessel is a cylinder with a piston to stop the water ...
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28 views

Question Regarding Boyle's Law

As the title suggests, i have a question regarding Boyle's law. As Boyle's law states that "The volume(V) of a given mass of a gas, is inversely proportional to the pressure(P) applied to it when the ...
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22 views

What is the average quadratic velocity of CO2 in this question?

I am working on this question, and I am unsure of how to proceed. The question is: There is $31.7~\mathrm{g}$ of $\ce{CO2 (g)}$ in a container. The partial pressure of $\ce{CO2}$ is ...
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17 views

How is the temperature of two gases in the same container calculated?

An air stream is contaminated by 100 ppm(on a molar basis) of compound X. 100ppm (parts per million) = 0.01 mol% = 10^-4 mol fraction. This may be a terribly dumb question and sorry if it is but, if ...
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46 views

Kinetic energy of an ideal gas

I've heard that the kinetic energy of any different gases are the same All gases at a given temperature have the same average kinetic energy. But if we have 2 moles of hydrogen and 4 moles of ...
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44 views

How is the ideal gas amount calculated?

Calculate the number of moles ($n$) and molecules of oxygen in your container from the ideal gas law ($pV=nRT$), assuming $T=300 \ \mathrm{K}$ ($R=0.0821 \ \mathrm{L \cdot atm/(mol \cdot K)}$). ...
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Calculating the energy released in cooling an ideal gas

Calculate the amount of energy released in cooling an ideal gas using the following information. Temperature change: 25 degrees celsius to 0 degrees celsius Volume of container: 5 litres (remains ...
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108 views

Gas of independent molecules

$$\begin{align} p &= kT\left(\frac{\partial \ln Q}{\partial V}\right)_T \\ &= \frac{kT}{Q}\left(\frac{\partial Q}{\partial V}\right)_T \\ &= \frac{NkT}{q}\left(\frac{\partial q}{\partial ...
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Similarity between all gases

How are gases all so similar unlike any other state of matter? For ex: 1) 1 mole of any gas will occupy 22.4 litres at atmospheric pressure. (Cannot be said of all solids/ liquids) 2) partial ...
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What is the effect of Van der Waals constants 'a' and 'b' on compressibility factor Z?

How does 'b' affect compressibility factor Z and liquefiability of a gas? I have thought a lot about it and cannot seem to understand this. Regarding 'a' I think I have got it. As 'a' increases the ...
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1answer
71 views

Which of the four balloons will shrink?

I had the test today and I am not sure about one of questions. Four gas balloons A, B, C, D of equal volumes containing $\ce{H2}$, $\ce{N2O}$, $\ce{CO}$, $\ce{CO2}$ respectively prickled with a ...
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High pressure modification to the van der Waals equation

I get that a gas behaves non-ideally under high pressure and low temperature conditions. At high pressures, the density of a gas increases and attraction forces operate among molecules due to short ...
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Alcohol Concentration of Liquid Compared to Surrounding Gas

I am aware of the standard methods of calculating ABV by measuring specific gravity before and after fermentation using a hydrometer or refractometer, but would it be possible to accurately measure ...
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47 views

How many liters of Cl2O can be produced by mixing 5.85L of SO2 and 9.00L of Cl2?

I just finished working out the problem below and was hoping to get some feedback on my method of solving. Dichlorine oxide is used as bactericide to purify water. It is produced by the chlorination ...
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Why does my eudiometer have this excess volume at the top?

It looks like this: The measurements start at 2 mL and the volume remaining in the top seems to be greater than 1 mL. What is the purpose? I am trying to measure hydrogen gas.
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Ratios and mass; reaction calculation problem

I have come across the following problem: One method used to inflate air bags in cars is to use nitrogen produced chemically from the decomposition of sodium azide. The sodium formed reacts with ...
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What's the empirical formula of this solid? Reacting mass calculation

I have come across the following problem: $1.00\ \mathrm g$ of sulphur dissolved completely in an excess of liquid ammonia to give $420\ \mathrm{cm^3}$ of hydrogen sulphide ($\ce{H2S}$), measured ...
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44 views

Gas Pressure and Molecular Mass

The ideal gas equation (or the van der Waals equation, for this matter) states that holding volume and temperature constant, increasing the number of moles of particles in the container will increase ...
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1answer
143 views

Number of grams of CO2 released from a carbonated water

The partial pressure of $\ce{CO2}$ gas in a bottle of carbonated water is $3.84\mathrm{~atm}$ at $25\mathrm{~^\circ C}$. How much $\ce{CO2}$ gas (in g) will be released from $0.5\mathrm{~L}$ of the ...
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60 views

Forces on piston in gas expansion

I'm slightly confused by a common situation in thermochemistry. Consider a container with gas inside and a movable, massless piston. The pressure of the gas inside is 6 atm and the external pressure ...
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21 views

Is my textbook using the law of partial pressures correctly?

My textbook shows that pressure fraction is equal to mole fraction because the same volume cancels: But it violates (if I am not mistaken) the law in this example it gives: the main components ...
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Kinetic theory of gases

The intermolecular distance between the molecules are much greater than the diameter of the gas molecules so we neglect their volume compared to the volume of container. "The rapidly moving particles ...
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PV=nRT approximation on other planets?

In Chemistry class yesterday, I learned that real gases with low atomic masses behave like an ideal gas at high temperatures and low pressure. Since on earth at sea level the pressure is close to $1\ ...
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Liquid-Nitrogen Powered Car

Students at the University of North Texas and the University of Washington built a car propelled by compressed nitrogen gas. The gas was obtained by boiling liquid nitrogen stored in 195.0 L tank. ...
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Calculating Delta H for Non Ideal Gasses

We have to calculate delta H for a gas that follows the Van der Waals equation of state: $$\left(p + \frac{a}{V_\mathrm m^2}\right)\left(V_\mathrm m-b\right)=RT$$ I know that $H = U + pV$ but I ...
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87 views

Pressure in Ideal Gas Law

In Boyle's law (P inversely proportional to V for constant n and T), P refers to the applied (external) pressure on the gas. However, in the ideal gas law, my textbook says that P refers to the ...
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54 views

Finding partial pressure

A mixture of argon (Ar) and CO2 was initially at a total pressure of 1.72 atm in a volume of 1.72 L at 17 ºC. The CO2 was then completely removed from the mixture by passing it through a solution of ...