2Na2CrO4 + H2SO4 = Na2Cr2O7 + Na2SO4 + H2O 4Na[+] +2CrO4[-] + 2H[+] + SO4[2-] = 2Na[+] + Cr2O7[2-] + 2Na[+] + SO4[2-] + H2O 2CrO4[-] + 2H[+] = Cr2O7[2-] + H2O