I have no idea how to answer this question: A compound effuses through a porous cylinder 3.20 time faster than helium. What is it’s molar mass?
Help me please? Give a step by step detail please.
To determine the molar mass of the compound, you can utilize Graham's law of effusion. This law states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass.
Let's break down the steps to find the molar mass of the compound using Graham's law:
Step 1: Compare the rates of effusion
The problem tells us that the compound effuses 3.20 times faster than helium. This means the ratio of the rates of effusion can be expressed as:
(rate of effusion of compound) / (rate of effusion of helium) = 3.20
Step 2: Set up the equation
Using Graham's law, we can set up the equation using the ratio of the rates of effusion:
(sqrt of molar mass of helium) / (sqrt of molar mass of the compound) = (rate of effusion of helium) / (rate of effusion of the compound)
Step 3: Substitute the known values
We know the rate of effusion of helium (1) and the ratio of the rates of effusion (3.20). Substituting these values into the equation, we get:
(sqrt of molar mass of helium) / (sqrt of molar mass of the compound) = 1 / 3.20
Step 4: Solve for the molar mass of the compound
To find the molar mass of the compound, we need to isolate the molar mass of the compound on one side of the equation. Start by cross-multiplying and then square both sides of the equation:
(sqrt of molar mass of helium) * 3.20 = sqrt of molar mass of the compound
(molar mass of helium) * 10.24 = molar mass of the compound
Step 5: Calculate the molar mass of the compound
Since the molar mass of helium (molar mass of an atomic nucleus) is approximately 4 g/mol, we can plug it into the equation and solve for the molar mass of the compound:
4 * 10.24 = molar mass of the compound
Molar mass of the compound ≈ 40.96 g/mol
Therefore, the approximate molar mass of the compound is 40.96 g/mol.