Complete and balance the following equations and identify oxidizing and reducing agents.
S+HNO3---->H2SO3+N2O
This is an oxidation/reduction reaction. There are rules to follow and that gives a balanced equation. Here is a site that gives the rules.
Show your work/repost follow up questions. You must work out the oxidation numbers of each element in order to know which elements have changed oxidation state. I will get you started.
S changes from zero on the left to +4 on the right. N changes from +5 on the left to +1 on the right. (Note: A good way to start this is to place a preliminary coefficient of 2 for 2HNO3. That is is order to compare two N atoms on the left with 2 on the right.)
http://www.chemteam.info/Redox/Balance-HalfReactions-Acid.html
To balance the equation S + HNO3 → H2SO3 + N2O, we need to ensure that the number of atoms on both sides of the equation is equal.
1. Begin by counting the number of atoms for each element on both sides of the equation:
On the left side:
1 Sulfur (S)
1 Nitrogen (N)
3 Oxygen (O)
1 Hydrogen (H)
On the right side:
2 Hydrogen (H)
1 Sulfur (S)
4 Oxygen (O)
1 Nitrogen (N)
2. Start with the most complex molecule and balance it last. In this case, it's HNO3.
3. Balance the Nitrogen (N) atoms by placing a coefficient of 2 in front of HNO3:
S + 2HNO3 → H2SO3 + N2O
4. Now, balance the Hydrogen (H) atoms by placing a coefficient of 4 in front of H2SO3:
S + 2HNO3 → 4H2SO3 + N2O
5. Finally, balance the Sulfur (S) atoms by placing a coefficient of 1 in front of S:
1S + 2HNO3 → 4H2SO3 + N2O
Now the equation is balanced:
S + 2HNO3 → 4H2SO3 + N2O
To identify the oxidizing and reducing agents, we need to examine the oxidation states of the elements involved.
In this case:
1. Sulfur (S) undergoes a change from an oxidation state of 0 to +4 in H2SO3. It is being oxidized, so Sulfur (S) is the reducing agent.
2. Nitrogen (N) is going from an oxidation state of +5 in HNO3 to 0 in N2O. It is being reduced, so Nitrogen (N) is the oxidizing agent.