if we did not use an excess of the BaCl2 solution it would decrease the mass percentage of sulfate in the unknown sample.
The net precipitation equation would be.
Ba2+(aq) + SO42-(aq) → BaSO4(s)
If BaCl2 (Ba2+) is not taken in excess then the precipitation would not be completed as some of the sulfate ions would still be remaining in the solution. This would decrease the mass percentage of sulfate in the unknown sample.
If some tiny pieces of filter paper still remained mixed with the precipitate(BaSO4) then the mass of sulfate would increase and it gives a high mass percentage of the sulfate.
mass percentage of sulfate = (mass of sulfate/mass of sample)*100
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Answer:
Dimer of two peptide chains with 1 mole of molybdenum metal each.
Explanation:
Percentage of molybdenum in protein = 0.08%
Molecular mass of nitrate reductase = 240,000 g
Mass of molybdenum = x
Moles of molybdenum =
Each peptide chain of nitrate reductase contain 1 mole of molybdenum.
This means that nitrate reductase is composed of to two peptide chains. And in each peptide there is a single mole of molybdenum metal.
please have look at Periodic table , you will solve it yourself !
Answer:
23
Explanation:
we do not care about electrons, so 11 + 12 = 23
