6.90 grams of metal carbonate was completely decomposed by 50 ml of 2N HCl.  The equivalent weight of metal is

NV(inml)1000=Wt of metalcarbonateeq.wt of metal carbonate50×21000=6.90eq.wt of metal carbonate∴        eq.wt of metal carbonate  = 6.90 x 10 = 69Eq.wt of metal  +Eq.wt of carbonate = 69Eq.wt of metal  + 30 = 69Eq.wt of metal= 69 – 30 = 39