Answer: 9.9 grams
Explanation:
To calculate the moles, we use the equation:

a) moles of 

b) moles of 


According to stoichiometry :
1 mole of
combine with 1 mole of
Thus 0.33 mole of
will combine with =
mole of
Thus
is the limiting reagent as it limits the formation of product.
As 1 mole of
give = 1 mole of 
Thus 0.33 moles of
give =
of 
Mass of 
Thus theoretical yield (g) of
produced by the reaction is 9.9 grams
Let us suppose that we have 1 mol of FeCr2O4. I'm going to use approximate masses because I have no idea what your periodic table will say. Just put in the exact masses from your periodic table.
Fe = 56
Cr*2 = 2*52 = 104
O4 = 4*16 = 64
===========
Total = 56 + 104 + 64 = 224
The % oxygen = (64 / 224) * 100 = 28.5 % but none of your answers match this. Perhaps you are talking about Fe2(Cr2O4)3 The brackets make all the difference in the world.
Without going through all the detail I did before, The molecular mass is
Fe * 2 = 112
Cr * 6 = 312
O * 12 = 192
The total molecular mass = 616
The % Oxygen = (192 / 616) * 100 = 31% roughly. That answer isn't there either.
Let's wait and see who else answers.
No chemical bonding take place.
And the elements or compounds in the mixtures have no definite proportions.
It has more electrons, meaning more orbitals, pls give brainliest.