Question

2KMnO4 + 16HCl X + KCl + 8H2O + 5Cl2 The oxidation state of Mn in 'X' is:

Answer 1

+2

Answer 2

The given chemical reaction is:

$2KMnO_4 + 16HCl \rightarrow X + KCl + 8H_2O + 5Cl_2$

To find the oxidation state of Mn in 'X', we first need to identify the chemical formula of 'X' by balancing the atoms on both sides of the equation.

1. Initial Atom Count (Reactants):

   • K: 2
   • Mn: 2
   • O: $2 \times 4 = 8$
   • H: 16
   • Cl: 16

2. Initial Atom Count (Known Products):

   • K: 1 (from KCl)
   • H: $8 \times 2 = 16$ (from $8H_2O$)
   • O: $8 \times 1 = 8$ (from $8H_2O$)
   • Cl: 1 (from KCl) + $5 \times 2 = 10$ (from $5Cl_2$) = 11

3. Balance Potassium (K):

   There are 2 K atoms on the reactant side ($2KMnO_4$) but only 1 K atom in the known products (KCl). To balance K, we need 2 molecules of KCl. The equation becomes: $2KMnO_4 + 16HCl \rightarrow X + 2KCl + 8H_2O + 5Cl_2$

4. Revised Atom Count (Known Products with 2KCl):

   • K: 2 (from 2KCl)
   • H: 16 (from $8H_2O$)
   • O: 8 (from $8H_2O$)
   • Cl: 2 (from 2KCl) + 10 (from $5Cl_2$) = 12

5. Determine the atoms in 'X':

   Compare the revised atom counts of known products with the reactant counts:

   • Mn: Reactants have 2 Mn, known products have 0 Mn. So, X must contain 2 Mn atoms.
   • Cl: Reactants have 16 Cl, known products have 12 Cl. So, X must contain $16 - 12 = 4$ Cl atoms.
   • All other atoms (K, H, O) are already balanced.

   Therefore, the formula of 'X' is $Mn_2Cl_4$. This can be simplified to $2MnCl_2$, which means 'X' is $MnCl_2$.

6. Calculate the oxidation state of Mn in 'X' ($MnCl_2$):

   In $MnCl_2$, chlorine (Cl) typically has an oxidation state of -1. Let the oxidation state of Mn be 'y'. $y + 2 \times (-1) = 0$ $y - 2 = 0$ $y = +2$

Thus, the oxidation state of Mn in 'X' ($MnCl_2$) is +2.

The balanced chemical equation is: $2KMnO_4 + 16HCl \rightarrow 2MnCl_2 + 2KCl + 8H_2O + 5Cl_2$

The oxidation state of Mn changes from +7 in $KMnO_4$ to +2 in $MnCl_2$.