How many grams of potassium dichromate are required to oxidise 20.0 g of Fe^(2+) inFeSO_(4) to Fe^(3+) if the reaction is carried out in an acidic medium ? (Molar mass of K_(2)Cr_(21)O_(7) and FeSO_(4)) are 294 and 152 respectively

How many grams of potassium dichromate are required to oxidise 20.0 g

1.	How many grams of potassium dichromate are required to oxidise 20.0 g of Fe^(2+) inFeSO_(4) to Fe^(3+) if the reaction is carried out in an acidic medium ? (Molar mass of K_(2)Cr_(21)O_(7) and FeSO_(4)) are 294 and 152 respectively
Answer» Solution :`Kr_(2)Cr_(2)O_(7)+4H_(2)SO_(4)rarrK_(2)SO_(4)+Cr_(2)(SO_(4))_(3)+4H_(2)O+3[O]` `2FeSO_(4)+H_(2)SO_(4)+OrarrFe_(2)(SO_(4))_(3)+H_(2)Oxx3` balanced REDOX reaction `K_(2)Cr_(2)O_(7)+6FeSO_(4)+7H_(2)SO_(4)rarrK_(2)SO_(4)+Cr_(2)(SO_(4))_(3)+3Fe_(2)(SO_(4))_(3)+7H_(2)O` It is evident from balanced equation that 6 moles of `FeSO_(4)=1` mole of `K_(2)Cr_(2)O_(7)` `therefore` 20 g of `FeSO_(4)` will require `K_(2)Cr_(2)O_(7)` `=(294)/(6xx152)xx20=6.45 g`