Question

0,1 moli aminoacid cu 3 atomi de carbon in molecula si care nu contine sulf poate reactiona cu 100g solutie NaOH de concentratie 4% si cu 31,4g solutie de Ch3-COOH 25%. Aminoacidul are un cotinut procentual(masic) de hidrogen egal cu ?

Answer 1

md=c*ms/100=4*100/100=4g
n=m/M=4/40=0,1moli NaOH=0,1moli aminoacid => raport de 1:1 => 1 gr COOH
md=c*ms/100=31,4*25/100=7,85g
n=m/M=7,85/60=0,130833moli
insa avand doar 0,1moli aminoacid => rezulta doar 0,1moli reactioneaza, cei 0,030833 moli raman nereactionati => 1 gr NH2
1gr NH2 + 1gr OH + 3 at de C => alanina
alanina are formula moleculara: C3H7NO2
Malanina=36+7+14+32=89g/mol
89g...............100%
. 7g....................x%
x=700/89=7,86% H