Question

in urma analizei elementale a 9 g subst organica s-au obtinut 2,8 g N2, 17,6 g CO2, si 12,6 g H2O.
determina formula moleculara a subst organice

Answer 1

17,6g CO2......xg C
44g CO2.......12g C
=> x=4,8 g

12,6g H2O..... yg H2O
18g H2O.........2g H2O
=> y=1,4 g

in 9g subst......4,8g C.....1,4g H.....2,8g N
in 100g subst.....a C .........b H.........c N

a=53,33% —> 53,33/12=4,44 moli C —>2atC
b=15,55% —> 15,55/1=15,55 moli H —>7atH
c=31,11%. —> 31,11/14=2,22 moli N. —>1atN

Formula bruta=(C2 H7 N)n