Question

A sample that weighs 107.75 g is a mixture of 30% helium atoms and 70% krypton atoms. How many particles are present in the sample?

Answer 1

To calculate the number of particles in the sample, we need to find the number of moles of helium and krypton. Once we have the moles, we can use Avogadro's number to convert the moles to the number of particles. The total number of particles in the sample is approximately 4.86 x 10^24 helium atoms + 5.41 x 10^23 krypton atoms.

Step-by-step explanation:

To find the number of particles in the sample, we first need to find the number of moles of each gas. We can use the percent composition to determine the masses of helium and krypton in the sample:

Mass of helium = 107.75 g x 0.30 = 32.325 g

Mass of krypton = 107.75 g x 0.70 = 75.425 g

Next, we can use the molar mass of each gas to calculate the number of moles:

Moles of helium = 32.325 g / 4.0026 g/mol = 8.07 mol

Moles of krypton = 75.425 g / 83.798 g/mol = 0.90 mol

Finally, we can use Avogadro's number to convert the number of moles to the number of particles:

Number of helium atoms = 8.07 mol x 6.022 x 10^23 atoms/mol = 4.86 x 10^24 atoms

Number of krypton atoms = 0.90 mol x 6.022 x 10^23 atoms/mol = 5.41 x 10^23 atoms

Therefore, the total number of particles in the sample is approximately 4.86 x 10^24 helium atoms + 5.41 x 10^23 krypton atoms.

Answer 2

A sample that weighs 107.75 g is a mixture of 30% helium atoms and 70% krypton atoms. How many particles are present in the sample? 3.59