Calculations using the Ideal Gas Law

In summary, the conversation involves using the ideal gas formula PV = nRT to solve for the number of moles (n) in a given system. The first step is to invert the formula and solve for n, and then the number of atoms can be determined by knowing how many atoms are in one mole of the ideal gas.
  • #1
ArcHorizon
3
1
Homework Statement
I got this question from one of the tutors, and they told me that this was a basic question. To me, it seemed to be a hard question, since it was my first time taking lessons for Physics Class.
So, this is the question.

[An ideal monatomic gas is kept in a container of volume 2.1 × 10–4 m3, temperature 310 K and pressure 5.3 × 105 Pa.]
[The volume of the gas is increased to 6.8 × 10–4 m3 at a constant temperature.]

a.i) State what is meant by an ideal gas.
a.ii) Calculate the number of atoms in the gas.
a.iii) Calculate, in J, the internal energy of the gas.
Relevant Equations
Not Sure This will help but
pV = nRT

Pressure in Pa
Volume in m^3
Temperature in kelvin
n is number of moles
R is gas constant
2.1 * 10^-4m/3 Temperature 310K
Pressure: 5.3 * 105 Pa
So the Ideal gas formula is PV = nRT
2.1*10^-4m^3 Times 5.3*105Pa = n * Gas Constant * Temperature
2.1*10^-4m^3 (*) 5.3*105Pa = # of moles *

I'm not sure what I was doing, but the whole equation stuff got hard and I stopped.
I left this question for 3 days, so I thought that I might ask for help.
 
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  • #2
ArcHorizon said:
2.1*10^-4m^3 Times 5.3*105Pa = n * Gas Constant * Temperature

You must invert the formula finding the number of moles ##n##, and after the number of atoms...
Ssnow
 
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  • #3
In your ideal gas equation

pV = nRT

all the quantities are given, except n. So solve for n. That is the first step. Now to nswer (ii), you need to know how many atoms thyere are in one mole of the ideal gas. Do you know that?
 
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FAQ: Calculations using the Ideal Gas Law

What is the Ideal Gas Law and how is it used in calculations?

The Ideal Gas Law is a mathematical equation that describes the relationship between pressure, volume, temperature, and number of moles of an ideal gas. It is used in chemistry and physics to calculate the properties of gases under various conditions.

What are the units of measurement used in the Ideal Gas Law?

The units of measurement used in the Ideal Gas Law depend on the variables being calculated. Pressure is usually measured in atmospheres (atm) or kilopascals (kPa), volume in liters (L) or cubic meters (m3), temperature in Kelvin (K), and number of moles in moles (mol).

How do you calculate the number of moles using the Ideal Gas Law?

To calculate the number of moles, you can rearrange the Ideal Gas Law equation to n = (PV)/(RT), where P is pressure, V is volume, T is temperature, and R is the ideal gas constant (0.08206 L·atm/mol·K). Make sure all units are consistent for accurate results.

What assumptions are made in the Ideal Gas Law equation?

The Ideal Gas Law assumes that the gas being studied is an ideal gas, meaning that it follows certain gas laws and has no intermolecular interactions. It also assumes that the temperature and pressure are constant and that the gas particles have no volume or mass.

How can the Ideal Gas Law be used to calculate the density of a gas?

The density of a gas can be calculated using the Ideal Gas Law by rearranging the equation to find density (d = PM/RT), where P is pressure, M is molar mass, and T is temperature. This equation is useful for determining the density of a gas at a specific temperature and pressure.

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