balance Redox :- CuS + SO4²- = CuO+SO2
H2O+CuS->CuO+2H++2e
4H++SO4^2-=SO2+2H2O
To balance the given redox equation: CuS + SO4²- = CuO + SO2, we need to follow a few steps.
Step 1: Determine the oxidation states of each element in the equation.
In this equation, we have Copper (Cu), Sulfur (S), Oxygen (O), and Sulfate ion (SO4²-).
Based on the rules for assigning oxidation numbers:
- Copper (Cu) typically has an oxidation state of +2.
- Sulfur (S) in CuS is -2 since it is a sulfide.
- Oxygen (O) typically has an oxidation state of -2.
- Sulfur (S) in SO4²- has an oxidation state of +6.
- Oxygen (O) in SO4²- has an oxidation state of -2.
Step 2: Identify the elements undergoing oxidation and reduction.
In this equation, Cu is undergoing an oxidation, as its oxidation state increases from 0 to +2. S is undergoing a reduction, as its oxidation state decreases from -2 to +6.
Step 3: Determine the change in oxidation numbers.
For Cu, the increase in the oxidation state is 2 (from 0 to +2), which means it gains 2 electrons. For S, the decrease in the oxidation state is 8 (from -2 to +6), which means it gains 8 electrons.
Step 4: Balance the atoms other than oxygen and hydrogen.
There is one Cu atom on each side, so no adjustment is needed for copper. For sulfur, we have one S atom on the left side of the equation and one S atom on the right side, so it is already balanced.
The equation now looks like this: CuS + SO4²- = CuO + SO2
Step 5: Balance oxygen atoms by adding water (H2O) to the side that lacks oxygen.
On the left side, we have 4 oxygen atoms from SO4²-, so we need to add 4 H2O on the right side.
The equation now looks like this: CuS + SO4²- = CuO + SO2 + 4H2O
Step 6: Balance hydrogen atoms by adding H+ ions to the side that lacks hydrogen.
On the right side, we have 4 H2O, which is equal to 8 H atoms, so we need to add 8 H+ ions on the left side.
The equation now looks like this: CuS + SO4²- + 8H+ = CuO + SO2 + 4H2O
Step 7: Balance the charge by adding electrons (e-) to the side that has a higher charge.
On the left side, we have 8 positive charges from H+, so we need to add 8 electrons (e-) on the left side to balance it.
The final balanced equation is: CuS + SO4²- + 8H+ + 8e- = CuO + SO2 + 4H2O
This equation satisfies the conservation of mass and charge.