The reaction of Mohr's salt and K2Cr2O7 is as follow: 6Fe2++Cr2O72−+14[H+]→6Fe3++2Cr3++7H2O n-factor of Cr2O72− is 6 and n-factor of Fe2+ is 1 . As n-factor for Fe is 1 so, Molarity = Normality Concentration of Mohr's salt =0.08M Moles in 25‌mL of 0.08M Mohr's salt =0.08×‌
25
1000
=0.002 ∴ Moles in 500 cc of Mohr's salt =0.002×‌
500
25
=0.04 Hence, mass of Mohr's salt in 500‌cc =0.04×392=15.68g