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CH1012
EMPIRICAL FORMULAE
Elemental
analysis
eg. to work out an empirical formula from
analytical data : C 55.15%, H 10.41% N 16.06%
i) find oxygen : 100 - (C% +H%+N%) = O%
eg. to work out an empirical formula from
analytical data : C 55.15%, H 10.41% N 16.06%
i) find oxygen : 100 - (C% +H%+N%) = O%
ii) find atom ratios:
C% H%
N% O%
55.15 /12.01 10.41 /1.01 16.06 /14.00 18.37 /16.00
55.15 /12.01 10.41 /1.01 16.06 /14.00 18.37 /16.00
iii)
divide all values by the smallest
number
4.590 10.327 1.147 1.148
4.590 10.327 1.147 1.148
4 9 1 1
iv) Empirical formula :
C4H9N1O1
calculate
M= (4x12)+(9x1)+(1x14)+(1x16) =87
compare with mass spec. [M]+ = 87
