Combustion analysis
Posted: Wed Jun 09, 2021 9:46 pm
This question presents analytical data from which you are required to determine mass % composition for a compound of up to four elements.
A sample of a compound containing C,H,S and Cl is subjected to combustion analysis to determine the quantities of C and H present. Using a second
sample, the S is analyzed by converting it to BaSO4 The results of the analysis are shown below.
Sample 1 Mass:2.711 ⇒ CO2 Mass:5.070;H2O Mass:2.276
Sample 2 Mass:4.243 ⇒ BaSO4:3.840
My answer:
Mass of C=Mass of CO2*12/44
5.070*12/44=1.383
% C=1.383/2.711*100= 51.00 %
Mass of H=Mass of H2O*2/18
2.276*2/18=0.253
% H=0.253/2.711*100= 9.33 %
The next element is determined similarly, using the second sample.
Mass of S=Mass of BaSO4*32.06/233.6
3.840 *32.06/233.6=0.5270
% S=0.5270/4.243*100=12.42 %
The final element is obtained by difference.
%Br=100-(51.00 + 9.33 +12.42) = 27.25 %
A sample of a compound containing C,H,S and Cl is subjected to combustion analysis to determine the quantities of C and H present. Using a second
sample, the S is analyzed by converting it to BaSO4 The results of the analysis are shown below.
Sample 1 Mass:2.711 ⇒ CO2 Mass:5.070;H2O Mass:2.276
Sample 2 Mass:4.243 ⇒ BaSO4:3.840
My answer:
Mass of C=Mass of CO2*12/44
5.070*12/44=1.383
% C=1.383/2.711*100= 51.00 %
Mass of H=Mass of H2O*2/18
2.276*2/18=0.253
% H=0.253/2.711*100= 9.33 %
The next element is determined similarly, using the second sample.
Mass of S=Mass of BaSO4*32.06/233.6
3.840 *32.06/233.6=0.5270
% S=0.5270/4.243*100=12.42 %
The final element is obtained by difference.
%Br=100-(51.00 + 9.33 +12.42) = 27.25 %