Balancing Equations Worksheet #2 featuring 20 chemical equations to balance, with a note about coefficients and a copyright notice from 2004 Cavalcade Publishing.

Let's solve each of these chemical equations by balancing them. The goal is to ensure the number of atoms of each element is the same on both sides of the equation.

---

1) Li₃PO₄ + NaOH → LiOH + Na₃PO₄

We have:
- Left: Li, P, O, Na, H
- Right: Li, O, H, Na, P

Try balancing:

- 1 Li₃PO₄ has 3 Li and 1 PO₄
- We need 3 LiOH on right → so 3 LiOH
- But then we get 3 Na from Na₃PO₄, so need 3 NaOH on left

So:
→ Li₃PO₄ + 3NaOH → 3LiOH + Na₃PO₄

✔ Balanced.

---

2) MgF₂ + Li₂CO₃ → MgCO₃ + LiF

Left: Mg, F, Li, C, O
Right: Mg, C, O, Li, F

- 1 MgF₂ → 1 MgCO₃ (Mg balanced)
- 1 Li₂CO₃ → 1 MgCO₃ (C and O balanced)
- But Li₂CO₃ has 2 Li → need 2 LiF on right
- So 2 LiF → need 2 F → but MgF₂ only gives 2 F → good

So:
→ MgF₂ + Li₂CO₃ → MgCO₃ + 2LiF

✔ Balanced.

---

3) P₄ + O₂ → P₂O₃

P₄ has 4 P atoms → need 2 P₂O₃ (which has 4 P)

So:
→ P₄ + 3O₂ → 2P₂O₃

Check:
Left: 4 P, 6 O
Right: 4 P, 6 O ✔

---

4) RbNO₃ + MgF₂ → Mg(NO₃)₂ + RbF

Look at:
- NO₃: RbNO₃ → Mg(NO₃)₂ needs 2 NO₃ → so 2 RbNO₃
- Then 2 Rb → need 2 RbF on right
- MgF₂ → one Mg → Mg(NO₃)₂ has one Mg → good
- But MgF₂ provides 2 F → 2 RbF needs 2 F → good

So:
→ 2RbNO₃ + MgF₂ → Mg(NO₃)₂ + 2RbF

✔ Balanced.

---

5) AgNO₃ + Cu → Cu(NO₃)₂ + Ag

This is a single displacement reaction.

Cu goes from 0 to +2 → loses 2e⁻
Ag⁺ gains 1e⁻ → becomes Ag⁰ → so need 2 Ag⁺ per Cu

So:
→ 2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag

✔ Balanced.

---

6) CF₄ + Br₂ → CBr₄ + F₂

CF₄ → CBr₄ → carbon stays, fluorine replaced by bromine

Need 4 Br to replace 4 F → so need 2 Br₂ (4 Br)

Then produce 2 F₂ (4 F)

So:
→ CF₄ + 2Br₂ → CBr₄ + 2F₂

✔ Balanced.

---

7) HCN + CuSO₄ → H₂SO₄ + Cu(CN)₂

Look at CN group:
- Cu(CN)₂ has 2 CN → need 2 HCN
- 2 HCN → 2 H → H₂SO₄ has 2 H → good
- SO₄ from CuSO₄ → H₂SO₄ → good
- Cu: 1 each side

So:
→ 2HCN + CuSO₄ → H₂SO₄ + Cu(CN)₂

✔ Balanced.

---

8) GaF₃ + Cs → CsF + Ga

Single displacement.

GaF₃ has 3 F → need 3 CsF → so 3 Cs

Then Ga produced

→ GaF₃ + 3Cs → 3CsF + Ga

✔ Balanced.

---

9) SrS + PtF₂ → SrF₂ + PtS

Swap partners: Sr with F, Pt with S

Each compound has 1 atom of each → so 1:1 ratio

→ SrS + PtF₂ → SrF₂ + PtS

✔ Balanced.

---

10) N₂ + H₂ → NH₃

Classic synthesis.

N₂ → 2N → need 2NH₃ → 6H → so 3H₂

→ N₂ + 3H₂ → 2NH₃

✔ Balanced.

---

11) LiF + Br₂ → LiBr + F₂

Single displacement.

Br₂ replaces F in LiF

But F₂ is diatomic → need even number of F

LiF → 1 F → F₂ needs 2 F → so 2 LiF

Then 2 Li → 2 LiBr

Br₂ → 2 Br → 2 LiBr → good

→ 2LiF + Br₂ → 2LiBr + F₂

✔ Balanced.

---

12) Pb(OH)₂ + HCl → H₂O + PbCl₂

Pb(OH)₂ has 2 OH → can form 2 H₂O if acid reacts

HCl → H⁺ and Cl⁻

Pb²⁺ needs 2 Cl⁻ → so 2 HCl

Then 2 H⁺ + 2 OH⁻ → 2 H₂O

So:
→ Pb(OH)₂ + 2HCl → 2H₂O + PbCl₂

✔ Balanced.

---

13) GaBr₃ + Na₂CO₃ → NaBr + Ga₂(CO₃)₃ (tough)

Note: Ga₂(CO₃)₃ means 2 Ga and 3 CO₃

So need 2 Ga → 2 GaBr₃
Then 2 GaBr₃ → 6 Br → need 6 NaBr → so 6 NaBr

Now Na₂CO₃: 6 Na → 3 Na₂CO₃
3 Na₂CO₃ → 3 CO₃ → matches Ga₂(CO₃)₃

So:
→ 2GaBr₃ + 3Na₂CO₃ → 6NaBr + Ga₂(CO₃)₃

✔ Balanced.

---

14) CH₄ + O₂ → CO₂ + H₂O

Combustion.

CH₄ → CO₂ → C balanced
H: 4 H → 2 H₂O → 2 H₂O

O: 2 H₂O has 2 O, CO₂ has 2 O → total 4 O → so 2 O₂

→ CH₄ + 2O₂ → CO₂ + 2H₂O

✔ Balanced.

---

15) Li₃PO₄ + CaCl₂ → LiCl + Ca₃(PO₄)₂ (tough)

Ca₃(PO₄)₂ → 3 Ca and 2 PO₄

So need 2 Li₃PO₄ → 2 PO₄ → 6 Li

Also need 3 Ca → 3 CaCl₂ → 6 Cl

Then 6 LiCl

So:
→ 2Li₃PO₄ + 3CaCl₂ → 6LiCl + Ca₃(PO₄)₂

✔ Balanced.

---

16) Na + Cl₂ → NaCl

Na → NaCl → needs 1 Na and 1 Cl

But Cl₂ has 2 Cl → so 2 NaCl → 2 Na

→ 2Na + Cl₂ → 2NaCl

✔ Balanced.

---

17) Ga + HCl → H₂ + GaCl₃ (last tough one)

Ga → GaCl₃ → needs 3 Cl → so 3 HCl

But 3 HCl → 3 H → makes 1.5 H₂ → not integer

So double:

2 Ga → 2 GaCl₃ → 6 Cl → 6 HCl → 6 H → 3 H₂

→ 2Ga + 6HCl → 3H₂ + 2GaCl₃

✔ Balanced.

---

18) N₂ + F₂ → NF₃

N₂ → 2 N → need 2 NF₃ → 6 F → 3 F₂

→ N₂ + 3F₂ → 2NF₃

✔ Balanced.

---

19) SO₂ + Li₂Se → SSe₂ + Li₂O

Swap: S from SO₂ with Se from Li₂Se

SO₂ → SSe₂ → need 2 Se → so 2 Li₂Se

Then 2 Li₂Se → 4 Li → need 2 Li₂O → 2 O

SO₂ has 2 O → good

So:
→ SO₂ + 2Li₂Se → SSe₂ + 2Li₂O

✔ Balanced.

---

20) NH₃ + H₂SO₄ → (NH₄)₂SO₄

NH₃ → NH₄⁺ → needs H⁺

H₂SO₄ → 2 H⁺ → so can make 2 NH₄⁺ → 2 NH₃

Then (NH₄)₂SO₄

→ 2NH₃ + H₂SO₄ → (NH₄)₂SO₄

✔ Balanced.

---

## ✔ Final Answers:

1) Li₃PO₄ + 3NaOH → 3LiOH + Na₃PO₄
2) MgF₂ + Li₂CO₃ → MgCO₃ + 2LiF
3) P₄ + 3O₂ → 2P₂O₃
4) 2RbNO₃ + MgF₂ → Mg(NO₃)₂ + 2RbF
5) 2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag
6) CF₄ + 2Br₂ → CBr₄ + 2F₂
7) 2HCN + CuSO₄ → H₂SO₄ + Cu(CN)₂
8) GaF₃ + 3Cs → 3CsF + Ga
9) SrS + PtF₂ → SrF₂ + PtS
10) N₂ + 3H₂ → 2NH₃
11) 2LiF + Br₂ → 2LiBr + F₂
12) Pb(OH)₂ + 2HCl → 2H₂O + PbCl₂
13) 2GaBr₃ + 3Na₂CO₃ → 6NaBr + Ga₂(CO₃)₃
14) CH₄ + 2O₂ → CO₂ + 2H₂O
15) 2Li₃PO₄ + 3CaCl₂ → 6LiCl + Ca₃(PO₄)₂
16) 2Na + Cl₂ → 2NaCl
17) 2Ga + 6HCl → 3H₂ + 2GaCl₃
18) N₂ + 3F₂ → 2NF₃
19) SO₂ + 2Li₂Se → SSe₂ + 2Li₂O
20) 2NH₃ + H₂SO₄ → (NH₄)₂SO₄

---

Let me know if you'd like this formatted as a printable worksheet or want explanations for any specific step!