Convert 6.50g ZnSO4 to moles.

6,50g of ZnSO4 is 0,04 moles

Mass of ZnSO4:

m=6,50g

Molar mass of ZnSO 4:

M=M (Zn) + M (S) + 4*M (O)

M=65,38 g/mol+32,06 g/mol+4*15,99 g/mol

M=161,40 g/mol

Molarity of ZnSO4:

n=m/M

n=6,50g/161,40g/mol

n=0,04 mol