Suppose you are given two flasks at the same temperature, one of volume 2 L and the other of volume 3 L. The 2-L flask contains 4.8 g of gas, and the gas pressure is x kPa. The 3-L flask contains 0.36 g of gas, and the gas pressure is 0.1x. Do the two gases have the same molar mass? If not, which contains the gas of higher molar mass?

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Identify the given information for each flask: Flask 1 has a volume of 2 L, contains 4.8 g of gas, and has a pressure of x kPa. Flask 2 has a volume of 3 L, contains 0.36 g of gas, and has a pressure of 0.1x kPa.

Use the ideal gas law, PV = nRT, to express the number of moles (n) for each flask. Since the temperature and R (ideal gas constant) are the same for both flasks, you can compare the moles of gas in each flask using the formula n = PV/RT.

Calculate the number of moles for Flask 1: n1 = (x * 2 L) / (RT).

Calculate the number of moles for Flask 2: n2 = (0.1x * 3 L) / (RT).

Determine the molar mass for each gas using the formula Molar Mass = mass / moles. Compare the molar masses to see if they are the same or which one is higher.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Ideal Gas Law

The Ideal Gas Law relates the pressure, volume, temperature, and number of moles of a gas through the equation PV = nRT. This law allows us to understand how gases behave under different conditions and is essential for calculating the number of moles of gas present in a given volume and pressure.

Molar Mass

Molar mass is defined as the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is a crucial concept for comparing the masses of different gases and determining their identities based on the amount of gas present and its mass.

Density of Gases

The density of a gas can be calculated using the formula density = mass/volume. In the context of the question, comparing the densities of the gases in the two flasks will help determine their molar masses, as gases with higher molar masses will generally have higher densities at the same temperature and pressure.

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