Balancing chemical equations worksheet for students to practice stoichiometry.

Final Answer:
(1) 1 S₈ + 8 O₂ → 8 SO₂
(2) 4 P₄ + 3 O₂ → 2 P₂O₃
Wait — correction: P₄ is the standard form, but the product is P₂O₃, which is unusual (normally P₄O₆). Let’s balance as written:
P₄ + 3 O₂ → 2 P₂O₃ → so (2) 1 P₄ + 3 O₂ → 2 P₂O₃

Actually, let’s carefully balance each one correctly:

(1) S₈ + 8 O₂ → 8 SO₂
✔ S: 8 = 8, O: 16 = 16

(2) P₄ + 3 O₂ → 2 P₂O₃
✔ P: 4 = 4, O: 6 = 6

(3) CF₄ + 2 Br₂ → CBr₄ + 2 F₂
✔ C:1=1, F:4=4, Br:4=4

(4) N₂ + 3 H₂ → 2 NH₃
✔ N:2=2, H:6=6

(5) 2 NaF + Br₂ → 2 NaBr + F₂
✔ Na:2=2, F:2=2, Br:2=2

(6) CH₄ + 2 O₂ → CO₂ + 2 H₂O
✔ C:1=1, H:4=4, O:4=4

(7) 2 K + Cl₂ → 2 KCl
✔ K:2=2, Cl:2=2

(8) 3 Li + AlCl₃ → 3 LiCl + Al
✔ Li:3=3, Al:1=1, Cl:3=3

(9) 3 Rb + P → Rb₃P
✔ Rb:3=3, P:1=1

(10) 2 Na + Cl₂ → 2 NaCl
✔ Na:2=2, Cl:2=2

(11) 4 Al + 3 O₂ → 2 Al₂O₃
✔ Al:4=4, O:6=6

(12) 2 KNO₃ → 2 KNO₂ + O₂
✔ K:2=2, N:2=2, O:6 = 4+2=6

(13) 2 KClO₃ → 2 KCl + 3 O₂
✔ K:2=2, Cl:2=2, O:6=6

(14) 2 HgO → 2 Hg + O₂
✔ Hg:2=2, O:2=2

(15) NH₄NO₂ → N₂ + 2 H₂O
✔ N:2=2, H:4=4, O:2=2
(Note: The formula given is NH₄NO₂ — ammonium nitrite — decomposes to N₂ and H₂O. Balanced as 1:1:2.)

So final answers:

(1) 1, 8, 8
(2) 1, 3, 2
(3) 1, 2, 1, 2
(4) 1, 3, 2
(5) 2, 1, 2, 1
(6) 1, 2, 1, 2
(7) 2, 1, 2
(8) 3, 1, 3, 1
(9) 3, 1, 1
(10) 2, 1, 2
(11) 4, 3, 2
(12) 2, 2, 1
(13) 2, 2, 3
(14) 2, 2, 1
(15) 1, 1, 2