Question

Prin oxidarea a 440g etanal cu reactivul Fehling cu un randament=75%, se depune o cantitate de precipitat rosu-caramiziu egala cu:
a. 1440g b. 1152g c. 1080g d. 1080kg e. 1152 kg

Answer 1

M,etanal= 44g/mol

M,Cu2O= 144g

1mol...............................................................1mol

CH3CHO + 2Cu(OH)2---> CH3COOH + Cu2O + 2H2O

44g.....................................................................144g

440g.......................................................................x= 1440g-masa teoretica

75/100= m,practica/m,teor---> m,pr= 1440x75/100g=......................calculeaza !