<span>Cr(NO3)3->Cr(OH)3->Cr2(SO4)3->Cr(OH)3->Cr2O3->Cr
Cr(NO3)3+3NaOH=Cr(OH)3</span>↓<span>+3NaNO3
2Cr(OH)3</span>↓<span>+3H2SO4=Cr2(SO4)3+6H2O
Cr2(SO4)3+6H2O=2Cr(OH)3</span>↓+3H2SO4
2Cr(OH)3=Cr2O3+3H2O
4Cr+3O2=2Cr2O3
2Cr2O3=4Cr+3O2
MgO + 2NAOH = Mg(OH)2 +NA2O 2Al + 6HCL =2AlCL3 +3H2 ZnO +2KOH = K2ZnO2 + H2O
1) Mr(N)=14
2)Mr(NaHCO3)= 23+1+12+16*3=84
3)Mr(CH3COOH)=12+1*3+12+16+16+1=90
4) Mr(HCL)=1+35=36
5)Mr(NACL)=23+35=58
6)Mr(C12H22O11)=12*12+1*22+16*11=342