There are two containers filled with gases. In both containers, gases are at the same temperature and presssure. The first container is 3 L and contains 0.9 moles of gas. The second container is 1 L. How many moles of gas are there in the second container?

If p is same and T is same then mols is proportional to volume.

If you have 1/3 the volume you must have 1/3 the mols.

To find the number of moles of gas in the second container, we can use the concept of the ideal gas law, which states that the pressure, volume, and temperature of a gas are related by the equation PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.

Since both containers have the same temperature and pressure, we can set up an equation using the ideal gas law for each container and solve for the number of moles in the second container.

For the first container:
P₁V₁ = n₁RT

For the second container:
P₂V₂ = n₂RT

Since the pressure and temperature are the same for both containers, we can set up the following equation:

P₁V₁ = P₂V₂

Now we can solve for n₂ by rearranging the equation:

n₂ = (P₁V₁) / (P₂V₂)

Given:
V₁ = 3 L
P₁ = P₂ (since both containers have the same pressure)
V₂ = 1 L
n₁ = 0.9 moles

Substituting these values into the equation, we get:

n₂ = (P₁ * V₁) / (P₂ * V₂)
= (P₂ * V₁) / (P₂ * V₂)
= V₁ / V₂

Substituting the values, we get:

n₂ = 3 L / 1 L
= 3 moles

Therefore, there are 3 moles of gas in the second container.