Value of R in Atm - Overview, Structure, Properties & Uses

Value of R in Atm - Value of Gas Constant, Formula, FAQs

Edited By Team Careers360 | Updated on Jun 09, 2022 02:06 PM IST

Gas constant R value

The gas constant, also known as the ideal gas constant or the molar constant, is an important physical constant that is denoted by the letter "R" and is utilized in most of the fundamental equations of thermodynamics, kinetic theory of gases, and so on. The ideal gas constant R is defined in physics as -Work done by the gas (or on the gas) per unit mole per unit temperature change. Boyle's law, Charles' law, Avogadro's law, and Gay-law Lussac's are all used to create the constant. The ideal gas law, the Arrhenius equation, and the Nernst equation all contain it as a physical constant.

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Gas constant R value
R-Value and What is the meaning of R
Value of R

The gas constant is a constant proportionality in physics that links the energy scale to the temperature scale and the measurement of the quantities of the substance. As a result, prior decisions and accidents in the definition of energy, temperature, and material amount eventually decide the value of the gas constant. The Boltzmann constant and the Avogadro constant, which separately connect energy to temperature and particle count to substance amount, were also determined.

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R-Value and What is the meaning of R

The gas constant is defined in physics as the product of pressure and volume. R is an abbreviation for energy per temperature increase per mole. Value of R in atm is a constant. However, the value of the gas constant can be stated in a variety of units. R is also known as the ideal gas constant, the universal gas constant, and the molar constant.

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As the pressure and volume of the system are changed, the value of R will change. Depending on the measuring system is being used, choose the appropriate R value.

The ideal condition is used to determine the R value under various scenarios.

Value of R in ideal gas equation

The ideal gas equation is used to calculate the value

PV=nRT

R=PV/nT

Where,

P is the ideal gas's pressure.

The volume of the ideal gas is represented by V.

The letter T stands for temperature.

The number of moles in a substance is indicated by n.

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Gas Constant Value

Universal gas constant R, which is a physical constant measured in units of energy per temperature increment per mole. The ideal gas constant, molar gas constant and universal gas constant are all interchangeable names. The gas constant is identical to the Boltzmann constant; however, it is expressed as the pressure-volume product rather than energy per temperature increment per particle.

The value of Ris equalled to 8.31445 J Mol-1K-1.

Universal Gas Constant Value

We can deduce from the ideal gas statement that

PV=nRT…….(1)

Where,

P is the ideal gas's pressure.

V is the ideal gas's volume.

n is the number of moles.

The universal gas constant R.

Temperature (T)

We get by rearranging the previous equation for R:

R=PV/nT………(2)

This is the formula for the gas constant.

The unit of R is given by, which is derived from equation (2).

R = (N/m2) x (m3)/ (mol) x (K)

R = N m/mol x K

(Newton-meter = Joule)

R = joule/mol x K

As a result, the gas constant R is measured in Joule/mol-K or J Mol-1K-1.

The following formula is used to value of R atstandard temperature and pressure).

Temperature is 273K, pressure is1.01105N/m2, and volume is 22.410-3m3 at STP for 1 mole of gas (n=1mol).

We find the gas constant value R by substituting these numbers in equation (2) and simplifying.

R = 8.31 J Mol-1K-1.

As a result, the value of R is J Mol-1K-1.

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Value of R

R value can be stated in a variety of unit systems depending on the necessity for calculation. We know, for instance, that 1 calorie = 4184 joules when you use the gas constant R value in calories, and then the value of R is.

R = 8.31/4.184 Cal Mol-1K-1.

Similarly, the gas constant R values can be expressed in a variety of units, as shown in the table below.

Value of R	Units of R
8.31	J mol⁻¹K⁻¹
1.98	Cal mol⁻¹ K⁻¹
8.31	m³(Pa)mol⁻¹K⁻¹
0.0821	L(atm) mol⁻¹K⁻¹
62.36	L(torr) mol⁻¹K⁻¹
1.98 x 10⁻³	k Cal mol⁻¹K⁻¹

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NCERT Physics Notes:

Frequently Asked Questions (FAQs)

1. Determine R value in L(atm) Mol-1K-1.

We know from the ideal gas equation that,

R=PV/nT

P=1atm, T=273K, and V=22.4L for n=1mol at STP,

By substituting the above values into the R equation,

R = 1 atm x 22.4 L/1 mol x 243 K

The required answer isR = 0.0821 L(atm) Mol-1K-1.

2. What are the various R values?

The value of the gas constant 'R' is determined by the pressure, volume, and temperature units used.

R = 0.0821 liter.atm/mol-K,

R = 8.3145 J/mol-K,

R = 8.2057 m3atm/mol-K,

R = 62.3637 L-Torr/mol-K,

3. In PV nRT, what is R?

PV=nRT, where n is the number of moles and the universal gas constant R is the ideal gas law. The value of R varies depending on the units used, but it is commonly expressed as R = 8.314 J/mol-K in S.I. units. As a result, the gas constant R value is equated to 287 J/kg-K can be used for air.

4. What's STP's R value?

The value of R is computed accordingly at atm i.e. at STP (standard temp and pressure). At STP, the temperature value is 273K, for 1 mole of gas (n=1 mol), the pressures are1.01105.

5. What is the universal gas constant R value?

The dimensions are energy per degree per mole of the universal gas constant R. The value of R is 8.314598 joules of kelvin (K) a mole in the meter-kilogram-second system.