Calculate the percentage by mass of magnesium in magnesium sulfate, MgSO4.Ar Mg = 24.31Ar S = 32.07Ar O = 16.00

Sure, here's how you calculate the percentage by mass of magnesium in magnesium sulfate (MgSO4):

1. First, calculate the molar mass of MgSO4. The molar mass is the sum of the atomic masses of all the atoms in a molecule.

   • The atomic mass of magnesium (Mg) is 24.31 g/mol.
   • The atomic mass of sulfur (S) is 32.07 g/mol.
   • The atomic mass of oxygen (O) is 16.00 g/mol, but since there are 4 oxygen atoms in MgSO4, the total mass contributed by oxygen is 4*16.00 = 64.00 g/mol.

   So, the molar mass of MgSO4 = 24.31 g/mol (Mg) + 32.07 g/mol (S) + 64.00 g/mol (O) = 120.38 g/mol.

2. Next, calculate the percentage by mass of magnesium in MgSO4. The formula to calculate the percentage by mass is:

   (Mass of the element / Molar mass of the compound) * 100%

   So, the percentage by mass of magnesium in MgSO4 = (24.31 g/mol / 120.38 g/mol) * 100% = 20.19%.

Therefore, the percentage by mass of magnesium in magnesium sulfate is approximately 20.19%.