Question

How many moles of MgSiO3 are in 237g of the compound?

Answer 1

First you need to calculate the molar mass of your compound by adding up the atomic weights.

Mg= 24.305 g/mol
Si= 28.0855 g/mol
O=15.999 * 3 oxygen atoms = 47.999 g/mol

Total atomic mass: 100.39 g/mol

This is your conversion factor to go from grams to mols.

Divide 237g by 100.39g/mol, grams cancel and you have 2.36 mols