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Cp=cv
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Does the relation Cp minus Cv equal R hold true for solids and liquids Why or why not?
No, this relation is ONLY for ideal gases. The difference between Cp and Cv can be written more generally as T*(dP/dT)v*(dV/dT)p, where the lower case v and p represent the derivatives taken at constant volume and pressure, respectively. If you take these two derivatives using the ideal gas law (PV=nRT), then the result simplifies to Cp-Cv=R. However, solids and liquids do not follow the ideal gas law, and the difference between Cp and Cv is much smaller... negligible in many cases. For solids, Cp-Cv can be calculated using the isobaric expansivity, isothermal compressibility, and density of the material.
What is a monatomic compound?
In physics and chemistry, monatomic is a combination of the words "mono" and "atomic," and means "single atom." It is usually applied to gases: a monatomic gas is one in which atoms are not bound to each other. At standard temperature and pressure (STP), all of the noble gases are monatomic. These are helium, neon, argon, krypton, xenon and radon. The heavier noble gases can form compounds, but the lighter ones are unreactive. All elements will be monatomic in the gas phase at sufficiently high temperatures. The only mode of motion of a monatomic gas is translation (electronic excitation is not important at room temperature). Thus in an adiabatic process, monatomic gases have an idealised γ-factor (Cp/Cv) of 5/3, as opposed to 7/5 for ideal diatomic gases where rotation (but not vibration at room temperature) also contributes. Also, for ideal monatomic gases: : the molar heat capacity at constant pressure (Cp) is 2.5 R = 20.8 J K-1 mol-1 (4.97 cal K-1 mol-1); : the molar heat capacity at constant volume (Cv) is 1.5 R= 12.5 J K-1 mol-1 (2.98 cal K-1 mol-1); where R is the gas constant.
How do you calculate the amount of electricity from biogas?
This would entirely depend on how efficient your biogas consuming electrical generator is and what the constituent gases in the biogas are. Biogas can contain between about 50-70% methane. The available energy in the biogas is derived from the calorific value (CV) of methane factored by the concentration of methane in the biogas. If you know the efficiency of the gas engine then you can derive the energy output from the known CV of the biogas input. It is important to select a suitable generator that can run on biogas and will provide suitable warranties when operating on biogas. It may be necessary to consider the impact of contaminant gases such as siloxanes, hydrogen sulphide and moisture in the biogas. It may be appropriate to protect the engine by installing scrubbing systems to clean the gas and remove the contaminants upstream of the engine in order to improve the lifetime of the equipment.
What is Specific heat at constant volume of natural gas?
Assuming your natural gas is 100% methane, the specific heat at constant pressure at 25°C:Cp/R = 4.217where R is the ideal gas constant represented in terms of energy.Using R=8.314 Joule/(Kelvin*mole)This yields Cp=35.06 J/(K*mol)The heat capacity at constant volume, Cv, is related to the heat capacity at constant pressure, Cp by the following expression:Cp-Cv=RTherefore Cv=Cp-R = 35.06 J/(K*mol) - 8.314 J/(K*mol) = 26.75 J/(K*mol)Assumptions:The system is a monotonic ideal gasThe temperature is at or near 25°CHeat capacity is not a function of temperatureA more accurate heat capacity as a function of temperature isCp/R = 1.702 + 9.081E-3*T - 2.164*T^(-2)where T is in Kelvins from 298K (25°C) to 1500K (1226.85°C)Assumptions 2 and 3 above do not apply to this.Source: Introduction to Chemical Engineering Thermodynamics. 7th Ed. by J.M. Smith, Appendix C p. 684
How do you calculate the concentration of hydrochloric acid from 23.74ml of 0.01470m NaoH for complete nutralisation of 25.00ml?
We use the formular CV=CV
How do you derive the equation cp-cv equals R?
cp-cv =R proved that//
What Cv and Cp of air?
1.005
What has the author Wilbert Frederick Koehler written?
Wilbert Frederick Koehler has written: 'The ratio of the specific heats of gases, Cp/Cv, by a method of self-sustained oscillations' -- subject(s): Heat, Gases
Does the relation Cp minus Cv equal R hold true for solids and liquids Why or why not?
No, this relation is ONLY for ideal gases. The difference between Cp and Cv can be written more generally as T*(dP/dT)v*(dV/dT)p, where the lower case v and p represent the derivatives taken at constant volume and pressure, respectively. If you take these two derivatives using the ideal gas law (PV=nRT), then the result simplifies to Cp-Cv=R. However, solids and liquids do not follow the ideal gas law, and the difference between Cp and Cv is much smaller... negligible in many cases. For solids, Cp-Cv can be calculated using the isobaric expansivity, isothermal compressibility, and density of the material.
Why cp and cv have different values?
Cv is a for a constant volume, and there is therefore no work done in the expansion whereas as Cp accounts for the work done by the gas during its expansion, as well as the change in its internal energy. Thusly Cp is generally bigger than Cv. Intuitively this would be very simple to work out yourself. We used to have to work this out ourselves back in my day, not just resort to cheap answers on the interweb.
Why Cp is greater Cv?
Because Cp has two functions:- 1-To change the internal energy dU. 2-To do work dW in expanding the gas. Where as Cv has only one function of changing the internal energy of the gas..by awais
Is CV an energy unit?
No. CV, as in "caloric value", is a measure of heating value; different units can be used, but any unit used is energy/mass, which of course is not the same as simply energy.
Do gases have specific heats?
Yes. Two specific heats are commonly defined: CV (constant volume specific heat and CP (constant pressure specific heat). For an ideal gas the relationship between the two can be calculated to be CP = CV + R The theoretical value of the specific heats for ideal gases can be estimated from the degrees of freedom of the gas - which in turn depends on it's structure. Monatomic gases really can only absorb energy by increasing their translational energy or boosting the electrons to higher orbitals. Diatomic gases add a degree of freedom for vibration and another for rotation (although diatomic molecules usually can store only and insignificant amount of energy in their rotations. Polyatomic molecules with more than two atoms have even greater degrees of freedom because they pick up vibrational modes for the additional molecular bonds and more rotational modes.
Why Cp is greater than Cv?
Because Cp has two functions:- 1-To change the internal energy dU. 2-To do work dW in expanding the gas. Where as Cv has only one function of changing the internal energy of the gas....by Hamoud Seif
Give expression for efficiency of dual cycle?
= 1 - qout/qin = 1 - cv(T4-T1)/(cv(Tx-T2)+cp(T3-Tx))
Explain how you can determine the atomicity of a gas?
To find the atomicity of an ideal gas you can use γ = Cp/Cv.
Why has a gas two values of molar heat capacities?
Gasses have two specific heat capacities because the boundary conditions can affect the number by up to 60%. Therefore, a number is given to each boundary condition: isobaric (constant pressure) or isochoric (constant volume). In an ideal gas, they differ by the quantity R (the gas constant - the same one you use in the ideal gas law): Cp = Cv + R where Cp is the isobaric molar heat capacity (specific heat) and Cv is the isochoric molar heat capacity.
