5.4 The Ideal Gas Law Lesson

Question 1

What components combine to form the ideal gas law, and what is the formula equation (Ideal Gas Law)?

Answer 1

By combining the three simple gas laws we form the expression that the volume of a gas is directly proportional to the number of moles of gas and to the temperature (in Kelvin) of the gas but is inversely proportional to the pressure of the gas; V= nT / P. We Replace the proportional sign with an equals sign by incorporating R, which is called the ideal gas constant;
[R = 0.08206 L atm/mol K].
V = RnT / P becomes PV = nRT, the ideal gas law.

Question 2

What is an ideal gas?

Answer 2

An ideal gas is a hypothetical gas that exactly follows the ideal gas law.

Question 3

What is the ideal gas constant?

Answer 3

The ideal gas constant is a proportionality constant (R) of the ideal gas law that is the same for all gases.
R = 0.08206 L atm/mol K

Question 4

What is the Gay-Lussac’s law, and what is its relationship to the ideal gas law?

Answer 4

The Gay-Lussac’s law states that as the temperature of a fixed amount of gas in a fixed volume increases, the pressure increases. This law takes the ideal gas law (PV = nRT), and rearranges the equation to P = nRT / V = (nR / V)T. Since n and V are constants and R is always a constant,
P = (constant) x T.

Question 5

What units of measure must be expressed within the ideal gas constant, R?

Answer 5

Pressure (P) in atm (atmospheres),
Volume (V) in L (liters),
Moles (n) in mol (moles),
Temperature (T) in K (kelvins).