This is not chemistry but it's A, off top.
We are told we have an oxyacid of the formula HOFO. We will assume the atoms are in this order and will draw a proper lewis structure for this compound by first drawing bonds between each of the 4 atoms and then place the remaining electron pairs on each atom:
.. .. ..
H - O - F - O:
·· ·· ··
We can calculate the formal charge of an atom using the following formula:
Formal charge = [# of valence electrons] - [# of non-bonded electrons + # of bonds]
H: Formal charge = [1]-[0+1] = 0
O: Formal charge = [6]-[4+2] = 0
F: Formal charge = [7]-[4+2] = +1
O: Formal charge = [6]-[6+1] = -1
As we can see the overall charge of the molecule is neutral since the fluorine as a +1 charge and the oxygen a -1 charge.
The mathematical expression for mass percent is given by:
Put the values,
mass of zinc = 
= 
or 65.4 g
Now, number of moles of zinc =
= 
= 1.00 mole
Number of atoms of zinc is calculated by the Avogadro number.
Now, according to mole concept
molecules of enzyme consists of atoms of zinc
So, 1 molecule of enzyme contains =
= 1 atom of zinc.
Hence, every carbonic anhydrase molecule consists of 1 atom of zinc.
