I need help with chemistry? I need help with mole?

Question

i need help with 2 problems. Please explain so i can understand how to do these

1. How many atoms of Kr contain 3.60 moles of Kr?

2. How many moles of SO3 contain 1.5 x 10^24 SO3?

Answer 1

1. The number of atoms in 1 mole of any compound or element is 6.0221415 × 10^23 atoms.

Therefore, in 3.60 moles, there is

6.0221415 × 10^23 * 3.60

so, atoms = 2,167,970,940,000,000,000,000,000

2. Using atoms = moles * Ar (avogradro's number)

moles = atoms / Ar

So, Moles = 1.5x10^24/6.0221415 × 10^23

So Moles = 2.49080829469052

So Moles = 2.491 mol (3 significant figures).

Answer 2

Think of a mole like a dozen - but much bigger. A dozen has 12 things in it, whether it's a dozen eggs, pencils or atoms. A mole has 6.02x10^23 things in it, whether it's a mole of eggs, pencils or atoms.

If you had 3.6 dozen atoms of Kr, you'd have 3.6 x 12 = 43.2 atoms. Since you have 3.6 moles Kr, it's 3.6 x 6.02x10^23 atoms = 2.17x10^24 atoms.

Answer 3

3.60molKr x 6.02x10^23atomsKr/1molKr = 2.17 x 10^24 atoms Kr

1.5 x 10^24moleculesSO3 x 1molSO3/6.02x10^23moleculesSO3 = 2.5 moles SO3

Answer 4

moles and atoms are related thru Avogadros number. (6.022E23 atoms in a mol)

1. You will have 3.6 * 6.022e23 = (calculate this)

2. 1.5E24/6.022E23 = (calculate this)

E means (times 10 to the whatever power)