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Sunday, October 11, 2020

How to calculate % free SO3 in given Oleum sample ?

CALCULATIONS OF FREE SO3 IN (X%) OLEUM SAMPLE :
Given - X %  labelled 100 gm Oleum,it means  (X-100) gm water required to destroyed all free SO3present in 100 gm Oleum.
                                               
WH2O= (X-100) gm
BY STOICHIOMETRIC CALCULATION:
Weight of SO= nSO3 X Molecular wt SO3

Weight of H2SO= nH2SO4 X Molecular wt of H2SO4
 
thus % (Free) SOpresent in 100 gm 109% labelled Oleum Sample is

What is the maximum % labelling of Oleum sample ?

For maximum possible labbelling amount of SO3 is 100 gm, It means 100 gm Oleum sample contains 100 gm SO3 only and zero( 0 )gm H2SO4 ,hence maximum labbelling possible is 122.5 %.

Saturday, October 10, 2020

Why Oleum is known as fuming Sulphuric acid?

(1) Oleum can be represented by the formulaySO3.H2O where y is the total molar sulphur trioxide content .the value of y can be varied to different Oleum sample.
(2) 
Oleum also be expressed  as H2SO4.xSO3where x is molar free suphur trioxide.
(3) 
Oleum is the solution of of sulphur trioxide in sulphuric acid , it is also known as  fuming sulphuric acid or Pyrosulphuric acid(H2S2O7=H2SO4+SO3).
(4) 
Oleum sample contain two type of SO3.

(i) Free SO3:- It is that SO3 which combined with water water to give H2SO4 .
(ii) Combined SO3:- The SO3 which is present in H2SO4 itself is known as combined SO3 and it does not react with water.

What is oleum formula?

(1) Oleum can be represented by the formulaySO3.H2O where y is the total molar sulphur trioxide content .the value of y can be varied to different Oleum sample.
(2) 
Oleum also be expressed  as H2SO4.xSO3where x is molar free suphur trioxide.
(3) 
Oleum is the solution of of sulphur trioxide in sulphuric acid , it is also known as  fuming sulphuric acid or Pyrosulphuric acid(H2S2O7=H2SO4+SO3).
(4) 
Oleum sample contain two type of SO3.

(i) Free SO3:- It is that SO3 which combined with water water to give H2SO4 .
(ii) Combined SO3:- The SO3 which is present in H2SO4 itself is known as combined SO3 and it does not react with water.