2NACRO 2 + 3BR 2 + 8 NAOH 2NA 2 CRO 4 +6 NABR+ 4 H 2 O

57/ 2NaCrO 2 + 3Br 2 + 8 NaOH 2Na 2 CrO 4 +6 NaBr+ 4 H 2 O