Question

un alcool polihidroxilic aciclic saturat reactioneaza cu un acid monocarboxilic aciclic saturat formand esterul cu masa moleculara 302,care contine de 5 ori mai multi atomi de carbon decat alcoolul.Stiind ca acidul are fata de alcool un atom de carbon in plus,alcoolul si respectiv acidul sunt?

Answer 1

alcool : CxH(2x+2-y)(OH)y
acid : CzH2zO2
z = x + 1     acid = C(x+1)H(2x+2)O2
yC(x+1)H(2x+2)O2 + CxH(2x+2-y)(OH)y ⇒ C(x+xy+y)H(2x+2+2xy)O(2y) + yH2O
x+xy+y = 5x   y(x+1) = 4x  y = 4x/(x+1)
12(x+xy+y) + 2x+2+2xy + 32y = 302
60x + 2x+2xy + 32y = 300    31x + xy + 16y = 150
31x +(x+16)·4x//(x+1) = 150
31x(x+1) + 4x(x+16) - 150x - 150 = 0
35x² -55x - 150= 0   7x² - 11x - 30 = 0    Δ = 121+ 840 =961
x = (11+31)/14 = 3   ⇒alcoolul are 3C; acidul are 4C
y = 3 ⇒ alcool= glicerina    acid = acid butanoic