The answer to 4 is A.
The answer to 5 is C.
Answer:
0.912 mL
Explanation:
3 Na2S(aq) + 2 FeCl3(aq) → Fe2S3(s) + 6 NaCl(aq)
FeCl3 is the limiting reactant.
Number of moles of iron III sulphide produced= 3.75g/87.92 g/mol = 0.043 moles
Hence actual yield of Iron III sulphide = 0.043 moles
Theoretical yield of Iron III sulphide = actual yield ×100%/ %yield
Theoretical yield of iron III sulphide= 0.043 ×100/75 = 0.057 moles of Iron III sulphide
From the reaction equation,
2moles of iron III chloride produced 1 mole of iron III sulphide
x moles of iron III chloride, will produce 0.057 of iron III sulphide
x= 2× 0.057= 0.114 moles of iron III chloride
But
Volume= number of moles/ concentration
Volume= 0.114/0.125
Volume= 0.912 mL
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.
Germanium is classified as a metalloid.