Ideal Gas Law

We use two R values: 0.0821 and 8.314. How do you know which to use for a problem?

• The units for pressure

• The units for temperature

• The units of volume

• The amount of moles

In the following, what is the unknown variable:

What is the volume of a balloon if it contains 3.2 moles of helium at a temperature of 20⁰C and 1.2 atm?

• P

• V

• n

• T

In the following, what will be the value for R:

What is the volume of a balloon if it contains 3.2 moles of helium at a temperature of 20⁰C and 1.2 atm?

• 0.0821 L⋅atm∕mol⋅K

• 8.314 L⋅kPa∕mol⋅K

• 293 K

• 1.2 atm

Which of the following variables is NOT correctly matched with its value for this problem:

What pressure is required to contain 0.023 moles of nitrogen gas in a 4.2 L container at a temperature of 20⁰C?

• V = 4.2 L

• R = 0.0821 L⋅atm∕mol⋅K

• n = 0.023 mol

• P = 20⁰C

Solve the following problem:

What is the volume of a balloon if it contains 3.2 moles of helium at a temperature of 20⁰C and 1.2 atm?

• 106.55 K

• 53.3 L

• 293 K

• 64.15 L

What is the correct value for T in the following problem:

What pressure is required to contain 0.023 moles of nitrogen gas in a 4.2 L container at a temperature of 20⁰C?

• T = 0.23 K

• T = 293 K

• T = 4.2⁰C

• T = 20⁰C

Solve the following probem:

What pressure is required to contain 0.23 moles of nitrogen gas in a 4.2 L container at a temperature of 20⁰C?

• 1.32 atm

• 0.048 atm

• 2.49 atm

• 19.32 atm

Choose the correct set of variables to solve the following problem: What is the volume of a balloon if it contains 3.2 moles of helium at a temperature of 20⁰C and 1.2 atm?

• P = x (unknown), V = 3.2 mol, n = 1.2 atm, T = 20⁰C K

• P = 1.2 atm, V = 3.2 mol, n = 20⁰C, T = x (unknown)

• P = 293 K, V = 3.2 mol, n = x (unknown), T = 1.2 atm

• P = 1.2 atm, V = x (unknown), n = 3.2 mol, T = 293 K

Choose the correct set of variables to solve the following problem: What is the volume of a balloon if it contains 3.2 moles of helium at a temperature of 20⁰C and 1.2 atm?

• P = x (unknown), V = 3.2 mol, n = 1.2 atm, T = 20⁰C K

• P = 1.2 atm, V = 3.2 mol, n = 20⁰C, T = x (unknown)

• P = 293 K, V = 3.2 mol, n = x (unknown), T = 1.2 atm

• P = 1.2 atm, V = x (unknown), n = 3.2 mol, T = 293 K

Choose the correct set of variables to solve the following problem:

What pressure, in kPa, is required to contain 0.23 moles of nitrogen gas in a 4.2 L container at a temperature of 20⁰C?

• P = x (unknown), V = 4.2 L, n = 0.23 mol, R = 8.314 L·kPa/mol·K, T = 293 K

• P = 4.2 L, V = 0.23 mol, n = x (unknown), R = 8.314 L·kPa/mol·K, T = 20⁰C

• P = 0.23 mol, V = x (unknown), n = 293 K, R = 0.0821 L·atm/mol·K, T = 4.2 L

• P = 20⁰C, V = 4.2 L , n = 0.23 mol, R = 0.0821 L·atm/mol·K, T =x (unknown)