Answer:
S + 6HNO₃ ⟶ H₂SO₄ + 6NO₂ + 2H₂O
Step-by-step explanation:
S + 6HNO₃ ⟶ H₂SO₄ + NO₂ + H₂O
One way is to balance this equation is the <em>oxidation number method</em>.
Step 1. Calculate the oxidation number of every atom:
S⁰ + H⁺¹N⁺⁵O₃⁻² ⟶ H₂⁺¹S⁺⁶O₄⁻² + N⁺⁴O₂⁻² + H₂⁺¹O⁻²
Step 2. Identify the changes in oxidation number:
S: +0 ⟶ +6; Change = +6
N: +5 ⟶ +4; Change = -1
Step 3. Equalize the changes in oxidation number.
You need 6 atoms of N for every 1 atom of S. This gives us total changes of -6 and + 6.
Step 4. Insert coefficients to get these numbers.
1S + 6HNO₃ ⟶ 1H₂SO₄ + 6NO₂ + H₂O
Step 5. Balance O.
We have fixed 18 O on the left and 16 O on the right. We need 2 more O on the right. Put a 2 in front of H₂O.
1S + 6HNO₃ ⟶ 1H₂SO₄ + 6NO₂ + 2H₂O
Every formula now has a coefficient. The equation should be balanced.
Step 6. Check that all atoms balance.
<u>Atom</u> <u>Left-hand side</u> <u>Right-hand side</u>
S 1 1
H 6 6
N 6 6
O 18 18
The balanced equation is
S + 6HNO₃ ⟶ H₂SO₄ + 6NO₂ + 2H₂O
