Question

Un amestec de efedrina si dopamina cu masa de 78,9g, in care cei doi compusi se afla in raport molecular A:B=2:3, contine 12,8 g de oxigen.ADEVARAT SAU FALS? +CUM SE REZOLVA.Multumesc anticipat!

Answer 1

MC10H15NO=165g/mol
MC8H11NO2=153g/mol

165x+153y=78,9=>165x+229,5x=78,9=>x=0,2 moli

x/y=2/3=> y=1,5x=>y=0,3 moli

raportul molar => x/y=0,2/0,3=2/3 (adevărat)

165x+153y.....................16x+32y
100..................................12,8

2112x+1958,4y=1600x+3200y=>512x=1241,6y => x/y=1241,6/512=620,8/256=155,2/64=38,8/16=19,4/8=9,7/4=1,94/0,8..

0,2*16+0,3*32=12,8g O (adevarat)