1) What is the mass of 5.24 moles of Fe504-7H2O?

Ok; first of all, you must correct the Molecular Formula; FeSO4•7H20

So, work out the Molar Mass;,

(4x18) O + 55.? Iron + 32 Sulphur, PLUS

(7x 18) H2O = 1 molar mass.

Now, take that times 5.24, show your work & check the Mol. Weights, I am going by memory.

Oxygen