How many moles of oxygen atoms are contained in 1.86 x 10-2 mol CuSO4·5H2O

Answer 1

There are 9 oxygen atoms in 1 molecule of CuSO4.5H2O (which is the same as saying there are 9 moles oxygen atoms in 1 mole of CuSO4.5H2O).
So 0.0186 moles CuSO4.5H2O must contain 9*0.0186 moles oxygen atoms.