How many moles are there in 7.25 × 1025 molecules of MgSO4?

Answer 1

To calculate the number of moles in a given number of molecules of a compound, you divide the number of molecules by Avogadro's number (6.022 x 10^23).

The formula for magnesium sulfate (MgSO4) shows that one molecule of MgSO4 contains one atom of magnesium, one atom of sulfur, and four atoms of oxygen.

Therefore, the molar mass of MgSO4 can be calculated as follows:

1 x atomic mass of magnesium (24.31 g/mol) + 1 x atomic mass of sulfur (32.07 g/mol) + 4 x atomic mass of oxygen (16.00 g/mol) = 120.37 g/mol

Now, we can use this molar mass to calculate the number of moles in 7.25 x 10^25 molecules of MgSO4:

7.25 x 10^25 molecules of MgSO4 / 6.022 x 10^23 molecules per mole = 120.44 moles

Therefore, there are approximately 120.44 moles in 7.25 x 10^25 molecules of MgSO4.