緊急!!兩條AL chem question ,有無人幫到我?thx!

slllo

1.A piece of impure iron wire weighs 0.2756 g.it is dissolved in acid,
oxidized to iron(ii) ions.The solution requires 40.8 cm3 of 0.020 M
acidified potassium dichromate solution for complete redox reaction.
What is the percentage purity of the iron wire?
(r.a.m. : Fe = 55.8)

2.15 gram of an unknown organic compound, CxHyOz, was completely
burnt in oxygen.The resulting gaseous mixture was passed through a
concentrated sulphuric acid and a potassium hydroxide solution.

The weight of the sulphuric acid and potassium hydroxide were increased by 1.351 g and 2.199g respectively.

a)What is the function of the concentrated sulphuric acid and potassium
   hydroxide solution?
b) Calculate the percentage composition of carbon,hydrogen and
    oxygen   in the unknown organic compound
c)Find the empirical formula of the unknown organic compound.
d) If the molar mass of the compound is 46 ,what is its molecular formula?
( r.a.m. : H=1 , C= 12, O=16)

[ 本帖最後由 slllo 於 2006-9-28  10:35 PM 編輯 ]