2Cr + O2 ---2CrO
CrO+H2SO4CrSO4+h2o
CrSO4+2NaOH Cr(OH)2+Na2SO4
2Cr+6HCl2CrCl3 +3H2
CrCl3+3NaOHCr(OH)3+3NaCl
2Cr(OH)3-+ t° Cr2O3 + H2O
2Cr + O2 ---2CrO
CrO+H2SO4CrSO4+h2o
CrSO4+2NaOH Cr(OH)2+Na2SO4
2Cr+6HCl2CrCl3 +3H2
CrCl3+3NaOHCr(OH)3+3NaCl
2Cr(OH)3-+ t° Cr2O3 + H2O