Question

va rog 40 puncte dau pls​

Answer 1

Vs = 500 mL = 0,5 L , p = 1,14 g/mL , Cm = 4,3 mol/L

metoda I:

Cm = md/MxVs ; M.HNO3 = 1+14+3x16 = 63 g/mol

=> md = CmxMxVs = 4,3x63x0,5 = 135,45 g HNO3 dizolvati

w% = mdx100/ms ; p = ms/Vs

=> ms = pxVs = 1,14x500 = 570 g sol. HNO3

=> w% = 135,45x100/570 = 23,76%

metoda II:

Cm = w%xpx10/M

=> w% = CmxM/10p = 4,3x63/10x1,14 = 23,76%