1. MCa(OH)2=74g/mol
n=m/M=148/74=2 moli Ca(OH)2
a) 1mol..........6.022*10^23 molecule
2mol............x=12.044*10^23molecule=12044*10^20 molecule
b) 2moli Ca(OH)2==> 4 atomi O si 4 atomi H
2. 1mol Cl2......6.022*10^23 molecule
x=4mol........24.044*10^23 molecule
3. 1mol N2.....6.022*10^23 molecule
x=2.166 mol....13.044*10^23 molecule
MN2=14*2=28g/mol
n=m/M==>m=n*M=2.166*28=60.648g N2
4. Cp=md/ms*100==>md=Cp*ms/100=45*830/100=373.5g Ca(HCO3)2
MCa(HCO3)2=40+2(1+12+3*16)=162g/mol
n=md/M=373.5/162=2.3 moli Ca(HCO3)2
Am notat "*" Înmulțire și "/" linia de fracție..