Ideal gas Definition and 823 Threads

Hi! I'm new to the forums and currently reading about Chemical Thermodynamics. So here's what I know: ΔE = q - w So for constant volume reactions, no work is done hence: ΔE = q But for constant pressure reactions, heat be may released (for exothermic reactions) and work is done hence: ΔE =...

Homework Statement [/B] Two balloons with Helium gas are filled, first with 10 liters of He and second with 20 liters. Molecules of which balloon will be moving faster as compared to the other? Homework EquationsThe Attempt at a Solution Speed of molecules is directly proportional to...

Homework Statement in this notes , i was told that the PV=mRT , why ? shouldn't PV= NRT , N=number of moles ? it should be PV = m/M (RT) , right ? Homework EquationsThe Attempt at a Solution

Homework Statement Methane at ## P_1 ## and ## T_1 ## is compressed to a pressure of ## P_2 ## adiabatically at steady-state. Calculate the work done on the compressor and the temperature ## T_2 ## of the discharge gas. Use ideal gas model. Given: ## T_1, P_1, P_2, C_p, \gamma = 1.4 ## ##...

Homework Statement Two well-insulated rigid tanks of equal volume, tank A and tank B, are connected via a valve. Tank A is initially empty. Tank B has 2 kg of Argon at 350 K and 5000 kPa. The valve is opened and the Argon fills both tanks. State 2 is the final equilibrium state. The temperature...

Homework Statement Does the specific heat of an ideal gas depend on the temperature only or does it depend on molecular weight and structure ? or both ? Homework Equations PV=mRT , Cp -Cv=R The Attempt at a Solution One of my teachers said it depends only on temperature and the other said...

Homework Statement Temperature, pressure and volume measurements performed on 1 kg of a simple compressible substance in three stable equilibrium states yield the following results. State 1 (T1=400 C , V1= 0,10 m3, P1=3 MPa) State 2 (T1=400 C , V1= 0,08 m3, P1=3,5 MPa) State 3 (T1=500 C , V1=...

Homework Statement If number of molecules in a closed container increases and it is kept at a constant tempurature, what happens to the pressure? I was confused because I thought if you add molecules the temputature would go up so keeping temputature a constant would have no affect on the...

Homework Statement I'm having a little trouble knowing when to use the ideal gas equations for entropy vs just the ones like this: (T2/T1)=(p2/p1)^((k-1)/k). I've noticed a pattern in the solutions for my homework( where you're finding isentropic efficiency of turbines and compressors) they...

Homework Statement One litre cylinder contains 1 mole of the ideal gas molecules having the average kinetic energy of 0.1eV. What is the total energy of this gas? Homework Equations W = K + U The Attempt at a Solution I figured because the cylinder is closed, no stated temperature change, or...

An ideal gas is compressed from a volume of Vi = 4.50 L to a volume of Vf = 3.00 L while in thermal contact with a heat reservoir at T = 295 K as in the figure below. During the compression process, the piston moves down a distance of d = 0.120 m under the action of an average external force of...

Qn : https://www.dropbox.com/s/dpcws9q4bjpzvtp/20151123_112037.jpg?dl=0 Why is option A and C wrong or correct? My attempted answer : A :A is plausible as if the piston is suddenly moved inwards, the gas molecules bounce off the piston at higher speeds Since Temp proportional to rms speed...

Homework Statement I have the following task: Homework EquationsThe Attempt at a Solution But I don't understand how to solve it. Can somebody help me?[/B]

Homework Statement 1 mm3 of gas at normal pressure and temperature contains about 1015 particles. Considering the particles as point-like and classical, provide a rough, conservative estimate for how many hard drives would be necessary to store the initial conditions of all gas particles. (As...

My daughter has the following homework problem we need assistance in confirming if we've understood and completed correctly. Homework Statement The Volume goes from 2.00 Liters to 7.00 Liters, the temperature changes from 800 kelvin to 150 kelvin, and the number moles of gas is quadrupled on...

Homework Statement I'm given a initial and final pressure and temperature of an ideal gas to solve for the work done after it expans in a polytropic process (n=1.2) Homework Equations W = integral of P*dV PV = nRT PV = RT* PV = mRT PV^n = Constant The Attempt at a Solution I get W = integral...

Homework Statement Assume that in an alternate universe, the laws of physics are very different from ours and that "ideal" gases behave as follows: (i) At constant temperature, pressure is inversely proportional to the square of the volume. (ii) At constant pressure, the volume varies directly...

Moderator's Note: THIS HOMEWORK WAS POSTED IN ANOTHER FORUM, SO THERE IS NO TEMPLATE. calculate the change in entropy suffered by 2 moles of an ideal gas on being heated from a volume of 100L at 50C to a volume of 150L at 150C. for the gas Cv=7.88 cal/moleC. I'm really confused in entropy and...

Homework Statement A specific type of ideal gas has a specific heat capacity at constant pressure (cp=cv+R) that is a function of temperature T, such that cp=0.5+876T, where cp has units of J/kg/K and T has units of K. The gas, which is initially at T1 = 294 K and P1 = 1x105 Pa, undergoes a...

Homework Statement One m3 of an ideal gas expands in an isothermal process from 760 to 350 kPa. Determine the specific work done by the gas. Homework Equations ω=W/m 1W2=mRTln(P1/P2) = P1V1ln(P1/P2) P1V1=P2V2 The Attempt at a Solution P1V1ln(P1/P2) = (760)(1)ln(760/350) = 589.29kJ...

Homework Statement Homework Equations Pv=nRt The Attempt at a Solution I already calculated V for a single molecule = 3.99x10^-23 m^3 and the cubic root of this volume gives 3.42x10^-8 m. However, I don't understand what I should do next. What does it mean to compare the value I obtained to...

Can someone please help me with the following proof ...I'm stuck and not sure if I'm even on the right path. Prove that What I've done so far; if U = f(T,V) dU = (∂U/∂T)v dT + (∂U/∂V)t dV Cv (non ideal) = (∂U/∂T)v Using dU = TdS - PdV and Maxwell relation (∂S/∂V)t =(∂P/∂T)v, (∂U/∂V)t =...

Homework Statement My problem is with the last line of the derivation. Usually, we take the rate of change of momentum (force) to be change of momentum divided by the impact time. But this slide of pp showed that the traveling time of the particle in the box is used but not the impact time. Why...

Hey guys, I just want to make sure I went about this the right way...your input would be greatly appreciated. Thank you in advance. 1. Homework Statement A tire is checked before a road trip and the gauge pressure reads 220 kPa (gauge) - State 1 The same tire is checked after the trip and the...

Homework Statement A sample of an ideal gas goes through the process shown in Figure P20.32. From A to B, the process is adiabatic; from B to C, it is isobaric with 100 kJ of energy entering the system by heat. From C to D, the process is isothermal; from D to A, it is isobaric with 150 kJ of...

If c_v is the specific heat at constant volume, authors substitute this into the first law as follows: c_v d\theta + pdv = dq How can one deduce that equation for any case? Since the specific heat at constant volume is used, the equation would be valid only where there is no expansion i.e...

A manufacturer quotes a standard CO2 canister contains 16g of CO2 at a volume of 20cm^3. So I need to calculate the pressure in the canister... Using ideal gas law P = nRT/V n = 0.364mol (16 of co2) R = 8.314 J/Kmol (universal gas constant) T = 294k (gas is at room temp 21 deg C) V = 20cm3...

It is well known that the ideal gas law applies only to an ideal gas, one consisting of particles infinitesimal in size and exhibits no interactions between the particles. Considering an ideal gas, is the ideal gas law valid under non-equilibrium conditions? For example, does the ideal gas law...

If you shake up a bottle of soda and it gets slightly larger because the disturbed gas in solution is trying to expand but cannot, could you use the difference in (THE SMALL AMOUNT THE BOTTLE ACTUALLY SWELLED) and the (POTENTIAL AMOUNT THE GAS WOULD SWELL IF NOT CONTAINED) to determine the...

I have a quick question regarding compressible fluid flow, specifically: for a given amount of time, how much pressure is lost when attaching a balloon valve to a small air tank. I decided to model my solution after the following problem (from an old fluid mechanics textbook of mine), Air is...

Say we are talking about an ideal gas. According to ideal gas law (PV=nRT), assuming the gas is now at absolute zero, if we further decrease the pressure of the environment, while keeping the container volume constant, will the gas goes under absolute zero? I wasn't an expert in Physics so...

Homework Statement A gas cylinder contains 4x10^4 cm cubed of hydrogen at a pressure of 2.5x10^7 Pa and a temperature of 290 K. The cylinder is used to foll balloons. Each balloon contains 7.24x10^3 cm cubed of hydrogen at a pressure of 1.85x10^5 and a temp of 290K when full. Find the number...

Homework Statement So first the task: Determine the average value of the kinetic energy of the particles of an ideal gas at 0.0 C and at 100 C (b) What is the kinetic energy per mole of an Ideal gas at these temperatures. I took the above right out of the pdf we got from our professor. I know...

Homework Statement Homework Equations PV=nRT The Attempt at a Solution not sure if this is the right approach plugging into -ρg gives us -PMg/RT = dP/dy now we have to integrate both sides to find P?

Homework Statement An ideal monatomic gas is contained in a cubic container of size ##L^3##. When ##L## is halved by reversibly applying pressure, the root mean square ##x##-component of the velocity is doubled. Show that no heat enters of leaves the system.Homework Equations ##dU = dQ -pdV##...

Homework Statement In an ideal gas at temperature T, the average force that a molecule applies on the walls of a closed container depends on T as Tq. A good estimate for q is: A. 2 B. 1 C. 1/2 D. 1/4 Homework Equations PV= nRT I think, Volume of container and moles are constant. So P ∝ T The...

Homework Statement Given: Ideal gas equations: Find S(T,V) for an ideal gas Homework Equations Ideal gas equations: \begin{array}{l} {\rm{}}\\ U = \frac{3}{2}N{k_B}{\left( {\frac{N}{V}} \right)^{2/3}}\exp \left[ {\frac{S}{{\left( {3/2} \right)N{k_B}}} - {s_0}} \right]{\rm{ }}\\ T = {\left(...

Hello, I know this has been fairly discussed to death, but I've had relative trouble finding a response that specifically addresses the n, in PV= nRT, the ideal gas law. Out of relatively common sense, by adding additional moles of gas, the pressure in the gas should increase as there are more...

Homework Statement \rho_0, c_0 is the mean density, the mean speed of sound in the ideal gas. Is the following correct? c(\rho)=c_0\left(\frac{\rho}{\rho_0}\right)^{\frac{\kappa-1}{2}} Homework Equations p = const * \rho^\kappa, c=\sqrt{\frac{\partial p}{\partial \rho}} The Attempt at...

Homework Statement Estimate partial pressure of nitrogen in atm in a room where you are at this moment. Use an ideal gas approximation and assume that air is composed of only nitrogen and oxygen. Show how you arrive the final answer in detail. Homework Equations pv=RT, while p stands for...

Here is a screenshot from a page from a textbook that explains how to derive the ideal gas law: In the third bold line, I don't understand how "time" in force = (change of momentum)/(time) is equal to 2x/u (the time it takes for the particle to travel to the opposite face and back again) -- I...

Homework Statement Derive an expression for the change in internal energy of 1 mol of an ideal gas for expansion from volume V_i to V_f under constant pressure of 1atm where \gamma = \frac{C_p}{C_v}=\frac{5}{3} Homework Equations \Delta U=\frac{3}{2}nR\Delta T PV=nRT The Attempt at a...

Hi there, I'm considering how the ideal gas law applies in practice in our planet's atmosphere. In particular, I'm considering this form of the law: P = ρRT (1) where P is pressure, ρ is density, R is the gas constant and T is the temperature. I also know that, to a good approximation, the...

Homework Statement An air bubble of volume 3.0x10-5m3 escapes from a divers equipment at a depth of 45m where the water temperatures is 5 degrees C. What is its volume as it reaches the surface, where the temperature is 12 degrees C? Atmospheric pressure = 101kPa, density of sea water =...

Homework Statement The volume of 30.0 moles of a monoatomic ideal gas is reduced at a uniform rate from 0.616m3 to 0.308m3 in 2h. Its temperature is increased at a uniform rate from 27.0◦C to 450◦C. The gas passes through thermodynamic equilibrium states throughout. (a) Write down explicitly...

Hi all, I have a question from a tutorial sheet that I'm stuck with. The question is Estimate the pressure at which a gas of argon atoms, at a temperature of 300 K, will begin to show deviations from the ideal gas behaviour due to the finite size of the atoms. Answer: Of order 10^9 Pa. So I...

So basically I was wondering whether it's possible to get the expression of ideal gas using molecular flux equation which is ##\phi = \frac{1}{4}\bar{v}n##. The derivation should be straightforward. I need to get the expression of pressure. Because the flux by definition already gives the rate...

I am working on a DIY project and want to understand the system/mathematical model of a traditional steam espresso machine. How I have started to think about the problem is a closed container with liquid and gas. At room temperature I know the vapor pressure of the water. As I increase the...

Homework Statement 10 moles of an ideal gas Cv = 20.8 J/mol at T0 = 300 K and P0 =0.3 MPa occupy the left half of an insulated vessel. At time t=0 a 1 kW electrical heating element is turned on. after 30 s, the partition dividing the vessel ruptures and the heating element is turned off...

Homework Statement Determine ΔSsys when 3.0 mol of an ideal gas at 25°C and 1 atm is heatedd to 125°C and expanded to 5 atm. Rationalize the sign of ΔSsys. Homework Equations State Function: dS = (dU)/T + (PdV)/T State Function for Entropy of Ideal Gas: dS = (CV,mdT)/T + (nRdV)/V Ideal gas...