Questions tagged [gas-laws]

Physical and chemical laws describing the properties and behavior of gases. This tag currently applies to properties and laws concerning both ideal and real gases.

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What are the limitations of the Theorem of Corresponding states?

I recently came across the theorem of corresponding states, which states that all gases exhibit the same compressibility factor, under same reduced pressure and temperature (and also the critical ...
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37 views

How to calculate Water and N2 is mixed together [on hold]

Water and $\ce{N2}$ is mixed together in a container, dissolved amount of $\ce{N2}$ is negligible (the container is lid by a piston). Initially, total pressure ($\ce{N2}$ + water) inside container ...
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41 views

Carbon dioxide concentration from pressure changes

Is there a way of determining the concentration of CO2 if we know the pressure in the container before the addition of CO2 and the pressure in the container after the addition of CO2 if we have no way ...
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1answer
27 views

What value should I use for P in the ideal gas equation for an unknown molar quantity?

I did a chemistry lab, in which baking soda and vinegar were reacted in a ziplock bag, and I was to calculate the proper quantity of reactants to fill the bag with CO2. The molar quantity of gas was ...
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A tricky question in Eudiometry/Gas analysis

In a eudiometer $\pu{14 ml}$ of $\ce{CH4}$ and $\pu{38.5 ml}$ of $\ce{O2}$ was introduced. After explosion and cooling to initial temperature ($\pu{23°C}$) the volume of eudiometer was found to be $\...
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32 views

Plotting phase diagram of mixed gas (Bubble and Dew points)

I'm developing a software which plots the Phase diagram (PT) for a mixed gas solution. I have the methods for Bubble and Dew points almost working. When I look at phase diagrams of commercial ...
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29 views

Avogadro's hypothesis [duplicate]

Under similar conditions of temperature and pressure, equal volumes of all gases contain equal number of molecules. But how is that possible? Suppose There is molecular chlorine and nitrogen. $\ce{Cl}...
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2answers
52 views

Having a contradiction while deriving Gay-Lussac's law using Boyle's law and Charles' law

From Boyle's law: $$P_1V_1 = P_2V_2 \quad\implies\quad V_2 = \frac{P_1V_1}{P_2} \label{eqn:boyle}\tag{1}$$ From Charles' law: $$\frac{V_1}{T_1} = \frac{V_2}{T_2} \quad\implies\quad V_2 = \frac{...
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Gas Law - increasing temperature with constant volume held

I've set up a simple experiment to look at the ideal gas laws. My experiment is relatively simple in that I have a metal tube which is capped on one side. I am then pressurising the tube with air to ...
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1answer
26 views

Understanding “Gay-Lussac's law of Gaseous volumes/combining volumes”

Understanding "Gay-Lussac's law of Gaseous volumes/combining volumes". So I was reading Wikipedia and stumble across this. It defines it as follows "The ratio between the volumes of the reactant gases ...
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1answer
25 views

Find ratio of quantities of water and of argon in airtight container

I am working on my EJU exam past papers (2013) and got stuck at this question. Knowledge of high school or first year university chemistry is assumed. I honestly do not know where I should start. ...
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18 views

Can we estimate if a substance will be in gas state at certain temperature?

Sometimes, by ballparking, we can estimate that a certain substance isn't in the gaseous state at room temperature because it has a large molecular weight. There is a direct relation between ...
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1answer
66 views

Calculating dew point and bubble point of gas mixtures

How do you calculate approximately the triple point and critical point of any given CH-based gas mixture? I have developed a software which uses iterations to find bubble point and dew point of any ...
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42 views

Mass of H2 in a balloon

Question A balloon of diameter $\pu{2 m}$ has a volume of $\pu{4190 dm^3}.$ It floats since it is given an up thrust equal to the mass of air it displaces. (Given: average $M_\mathrm{r}$ of ...
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1answer
54 views

Predicting pressure inside a container based on temperature

I'm a mathematician and computer scientist, and for this particular problem I would benefit from some chemical expertise. Suppose I fill a container up with some liquid propane. I believe this is ...
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23 views

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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41 views

Trying to understand rationale behind Joule-Thomson experiment

The purpose of the original Joule (as opposed to JT) expansion experiment was to assess intermolecular interactions in real gases. In that experiment, Joule immersed twin glass globes into a water ...
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Saturation dissolved oxygen level at pressure

The saturation level of dissolved oxygen in contact with a moist atmosphere is $$c = 0.21(p_\mathrm{atm} - p_\mathrm{vap}) K_\mathrm{H} M$$ where the $p_\mathrm{atm}$ and $p_\mathrm{vap}$ are the ...
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2answers
61 views

How to measure quantities at standard state when this state is a hypothetical one?

Consider the reaction $$\ce{A(g) + H2O(l) <=> B(aq) + C(g)}$$ If all gases and solutions were ideal, the standard state would be pure water, the solute B at a concentration of 1 M, the gases A ...
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2answers
95 views

Molarity Numerical on Water Gas Shift Reaction

For the water gas shift reaction below, $K_c = 3.491$ at a certain temperature. What are the equilibrium concentrations of all the components of the reaction if $\pu{0.3815 mol}$ of $\ce{CO}$ and $\ce{...
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2answers
469 views

Can the van der Waals coefficients be negative in the van der Waals equation for real gases?

A gas described by van der Waals equation has the pressure that is lower than the pressure exerted by the same gas behaving ideally. True or false? My approach $$P(\text{ideal}) = P(\text{real}) + P(...
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1answer
45 views

Relationship between rate of reaction and pressure

Given the equation $$\ce{A(g) + B(g) → C(g) + D(g)}$$ with reaction rate given by $$v = k[\ce{A}]^2$$ How can I prove that reaction rate goes up with pressure? I tried substituting $k$ for $Ae^{-...
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63 views

How to derive the compressibility factor for a van der Waals gas?

So as far as I know, $$Z=\frac{p_\mathrm{r}V_\mathrm{r}}{nRT},$$ where $\mathrm{r}$ denotes the subscript for real. Solving it for a van der Waals gas gave me the following result, $$Z=1+\frac{p_\...
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2answers
134 views

Compressibility Factor Of Gases

In the general equation of the compressibility factor $Z$, we define $Z$ as $$Z=\frac{pV}{nRT}$$ Here, what is $p$? Is it $p_\text{real}$ or $p_\text{ideal}$? Also, what is $V$? $V_\text{real}$ or $V_\...
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2answers
78 views

Relationship between the ideal gas constant and entropy

So it dawned on me the other day that the ideal gas constant $$R = \pu{8.31 J mol-1 K-1}$$ has the same units as molar entropy. Is there some deeper meaning behind this or is it just a coincidence ...
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34 views

For azeotropic mixtures, is the total vapour pressure at equilibrium equal to the partial pressure of one of the components?

I know, a ridiculous statement. But here's how I reached at it . Say we have a solution of two components liquids A and B. By Raoults law, $$p_A= p_A^o \times x_A \tag1$$ Also by Dalton's law, $$...
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55 views

Pressure of Gas Collected Over Water

My textbook, as well as practically every online source I have looked into, says that when you collect gas over water, the pressure of the trapped gas plus the vapor pressure of water at that given ...
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1answer
63 views

Why 1 mole of H2 occupied the same volume occupied by 1 mole of O2?

I'm asking a question about the volume occupied by gasses in standard temperature and pressure. My textbook said that a mole of any gas occupies 22.4 L at standard temperature and pressure. But ...
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1answer
90 views

if a balloon full of warm air was placed in a refrigerator, what is the result? [closed]

If a balloon full of warm air was placed in a refrigerator, What will happen to the Ballon ?
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1answer
132 views

Are the vibrational modes of CO2 active at room temperature?

I was doing an experiment whereby I had to measure the specific heat ratios of certain gases. Carbon dioxide came out to be around 1.3, and checking with the accepted values this is close. My question ...
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112 views

Volume of dried gas at STP

A $54.0\ \mathrm{mL}$ sample of oxygen is collected over water at $20\ \mathrm{^\circ C}$ and $770\ \mathrm{Torr}$ pressure. What is the volume of the dry gas at STP? By using the combined gas law, I ...
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85 views

What will be unit of volume in V=nRT/p if p is in Torr instead of atm? [closed]

$V=nRT/p$, where $n$ is amount of gas in $\mathrm{mol}$, $R$ is gas constant, $V$ is volume in $\pu{dm3}$, and $p$ is pressure in $\pu{atm}$. What happens to $R$ if $p$ is in $\pu{Torr}$ instead of $...
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176 views

The respective speed of five molecules are 2, 1.5, 1.6, 1.6 and 1.2 km/s. The most probable speed in km/s will be?

The respective speed of five molecules are 2, 1.5, 1.6, 1.6 and 1.2 km/s. The most probable speed in km/s will be? 1. 2 2. 1.58 3. 1.6 4. 1.31 I think the answer should be 1.6 km/h but the ...
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2answers
170 views

Derivation of work done by real gas

According to the Wikipedia on real gases, it is stated that the expansion work done by a real gas differs from the ideal gas by $\int\left(V-\frac{RT}p\right)\,\mathrm dp$. Firstly, does this mean $...
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1answer
69 views

Solving a quadratic of for pressure of real gas with unknown volume

I had this question on my test: Calculate the pressure exerted (in atm) by 1 mole of $\ce{CH4}$ gas at a temperature of $\dfrac{24}{0.0821}$ K if volume occupied by $\ce{CH4}$ molecules ...
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1answer
80 views

Compressibility factor of hydrogen at low pressure and constant temperature

As we all know, the compressibility factor $Z$ of hydrogen and helium is always greater than $1$ at a constant moderate temperature. But, if we look at the virial equation of compressibility factor $$...
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2answers
513 views

Entropy change of isothermal irreversible expansion of ideal gas [duplicate]

Two mole of an ideal gas is subjected to isothermal expansion from $\pu{2 atm}$ to $\pu{1 atm}$ at $\pu{300 K}$. Calculate entropy change of the system, surrounding and total, if the process is ...
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1answer
100 views

Real gas equation at high molar volume

How would the van der Waals equation of state look like when molar volume of gas is high? Does high molar volume correspond to low pressure? My textbook says that A real gas behaves similar to an ...
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4answers
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How could the ideal gas law be discovered from experiments on real gases?

The gas laws, namely Boyle's Law, Charles' Law, Avogadro's Law and Gay-Lussac's Law, are all experimental laws. Combining these laws, we get the ideal gas law $pV=nRT$. Also, "real life" gases do not ...
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1answer
85 views

How to calculate the volume or mass of carbon dioxide gas absorbed by a calcium hydroxide solution?

Carbon dioxide reacts with calcium hydroxide as shown by the equation: $$\ce{Ca(OH)2 (aq) + CO2 (g) -> CaCO3 (s) + H2O (l)}$$ A solution containing $\pu{0.1 mol}$ of calcium hydroxide reacts ...
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1answer
41 views

Volume of air required to oxidize glucose

In the body, the oxidation of glucose is according to the reaction: $$\ce{C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O}$$ Knowing that glucose consumption is $\pu{2.47 mol/d}$, What is the volume of ...
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1answer
27 views

Combination of several unit symbols when finding new pressure from ideal gas law

As a car is driven, the tires heat up and the volume and the pressure change. Calculate the new pressure of a 35.0 L tire initially at 235 kPa that expands to 36.5 L when it heats up from 15.0 °C to ...
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1answer
74 views

How to calculate the standard Gibbs energy at equilibrium?

Given that $K_c = 1.7 \times 10^{-13}$, calculate $\Delta G^{\circ}$ for this equilibrium mixture at $\pu{298 K}$. $$\ce{N2O (g) + \frac{1}{2}O2 (g) <=> 2 NO (g)}$$ I've calculated: $$ \...
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2answers
58 views

Finding percentage of the gas in a binary gaseous mixture of the given density

At STP, the density of a gas in a vessel is $0.9002$. If the gas is a mixture of argon and helium, what percentage of the gas is argon? I am stuck on this. From what I can gather, the only ...
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4answers
123 views

Adiabatic processes and the Ideal Gas Law [closed]

in my first year chemistry textbook it wrights that in adiabatic proccess when there is a system of canister filled with gas and a piston above(and wheights on it) if we let the piston move upward by ...
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1answer
85 views

Why is excluded volume in van der Waals equation divided by 2?

Source: Physics Stack Exchange The excluded volume calculated based on the diagram is 8 times the volume of a molecule. The volume is then divided by 2 to give the so-called excluded volume per ...
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1answer
398 views

Compressibility Factor Graph - Which gas attains a deeper minimum?

As in the given graph, how do I predict which curve among that of hydrogen, methane, and carbon dioxide attains a deeper absolute minimum? (greater deviation from Z=1). In fact, how do I make this ...
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Determining mole fraction of carbon dioxide knowing Kp only

I've been assigned the following problem at school: Given the following reaction: $$\ce{C (s) + CO2 (g) <=> 2 CO (g)}$$ Find the mole fraction of $\ce{CO2}$ provided that, in ...
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1answer
71 views

What is the radius of the atoms? [closed]

In a recipient there is an unknown monoatomic gas that occupies a volume of $\pu{230 cm3}$, at $\pu{300 K}$ and $\pu{1 atm}$. It is known that the atoms occupy a volume of $2\times10^{-4}$. Find the ...
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1answer
178 views

What is the temperature dependency of the van-der-Waals constants? [closed]

What is the effect of the temperature on the van-der-Waals constants $a$ and $b$? I have checked on the effect of pressure and volume on the van-der-Waals constants, but I've not been able to get the ...