The sum of the coefficients in the balanced equation is:
1 (in front of H2SO4) + 2 (in front of H2) + 2 (in front of I2) + 1 (in front of SO2) = 6
So, the answer is C) 6.
To balance the molecular equation for the redox reaction:
H2SO4(aq) + H2(g) → I2(s) + SO2(g)
We need to make sure that the number of atoms of each element is the same on both sides of the equation. Here's how to balance it step by step:
1. Balance the non-hydrogen and non-oxygen atoms first:
H2SO4(aq) + H2(g) → I2(s) + SO2(g)
There is 1 sulfur (S) atom on both sides, 2 oxygen (O) atoms on both sides, and 2 hydrogen (H) atoms on both sides, so they are already balanced.
2. Balance the hydrogen (H) atoms:
H2SO4(aq) + H2(g) → I2(s) + SO2(g)
On the left side, there are 2 hydrogen atoms, and on the right side, there are none. To balance the hydrogen atoms, add a coefficient of 2 in front of H2 on the right side:
H2SO4(aq) + 2H2(g) → I2(s) + SO2(g)
3. Balance the iodine (I) atoms:
H2SO4(aq) + 2H2(g) → I2(s) + SO2(g)
On the left side, there are 2 iodine atoms (I2), and on the right side, there is only 1 iodine atom. To balance the iodine atoms, add a coefficient of 2 in front of I2 on the right side:
H2SO4(aq) + 2H2(g) → 2I2(s) + SO2(g)
Now, all the atoms are balanced.
4. Check if the charges are balanced in case this is an ionic equation (oxidation-reduction reaction). In this case, we see that the charge is balanced (0 on both sides).
So, the balanced molecular equation is:
H2SO4(aq) + 2H2(g) → 2I2(s) + SO2(g)