1 mH3PO4=196 kg
nH3PO4=?
MH3PO4=3*1+31+4*16=98
n=m/M=196g/98g/mol=2 moli
2. nNa2SO4=0,5 Kmoli
mNa2SO4
MNa2SO4=2*23+32+4*16=142 u.am
m=n*M=0,5kmlo*142 Kg/Kmoli=71 kg
3. m CaCl2=111Kg
ne molecule =?
McaCl2=40+2*35,5=111 u.am
111kg conține 6.023 X10 (23)
4. nH2S=2,5
nr atomiH=?
1moli 2 atomiH
2,5 x=5 atomiH
5. VP2O5=?
nr molecule=2X6,023X10(23)
22,4l.............6,023X10(23)
x 2X6,023X10(23)
x=44,8 l