Hey there! I’m happy to help!!
To convert grams to moles, you divide the grams by the molar mass of the substance. This is obtained by adding the atomic masses of each atom in the molecule. The molar mass of potassium sulfate (K2SO4) can be calculated to be 174.259 g. Now we divide.
5.25/174.259= 0.030 moles
I hope this helps!!