Question

write the net ionic equation for the reaction of potassium dichromate (vi) K2Cr2O7 with sodium sulphite , Na2SO3 in acid solution to give chromium (iii) ion and sulphate ion .

Answer 1

Answer : The net ionic equation will be,

$Cr_2O_7^{2-}+8H^++3SO_3^{2-}\rightarrow 3SO_4^{2-}+2Cr^{3+}+4H_2O$

Explanation :

In the half reaction method, the number of atoms in each half reaction and number of electrons should be balanced.

The half reactions in the acidic medium are :

Reduction : $Cr_2O_7^{2-}+14H^++6e^-\rightarrow 2Cr^{3+}+7H_2O$   ......(1)

Oxidation : $SO_3^{2-}+H_2O\rightarrow SO_4^{2-}+2H^++2e^-$      .......(2)

Now multiply the equation (2) by 3 and then added both equation, we get the balanced redox reaction.

Thus, the balanced redox reaction will be,

$Cr_2O_7^{2-}+8H^++3SO_3^{2-}\rightarrow 3SO_4^{2-}+2Cr^{3+}+4H_2O$

Answer 2

Answer:

here is the required answer