Respuesta :

Molar mass MgC₂O₄ = 112.3240 g/mol

1 mole ---------- 112.3240 g
? mole ---------- 3.25 g

moles = m / molar mass

moles = 3.25 / 112.3240

= 0.0289 moles

hope this helps!
MgC₂O₄

From Periodic table, Mg = 24, C = 12, O = 16.

MgC₂O₄ = 24 + 2*12 + 4*16 = 24 + 24 + 64 =  112

112 grams  is actually  1 mole of  MgC₂O₄

1 gram will be :            (1/112) mole of MgC₂O₄

3.25 grams will be  =   3.25 / 112 = 0.029

3.25 grams is ≈ 0.029 Mole