Let’s go step by step through each problem. We’ll identify the reaction type for Part A, and for Part B we’ll balance the equation first, then identify the type.
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Part A: Identify each type of chemical reactions
1) C₉H₂₀ + 14 O₂ → 9 CO₂ + 10 H₂O
This is a
combustion reaction — a hydrocarbon (C₉H₂₀) reacts with oxygen to produce carbon dioxide and water.
2) SrCl₂ + 2 AgNO₃ → Sr(NO₃)₂ + 2 AgCl
Two compounds swap partners: Sr pairs with NO₃, Ag pairs with Cl. This is a
double replacement reaction.
3) 2 LiBr + F₂ → 2 LiF + Br₂
Fluorine replaces bromine in the compound. One element kicks out another from a compound. This is a
single replacement reaction.
4) 2 NaF → Na + F₂
One compound breaks down into two elements. This is a
decomposition reaction.
5) ZnBr₂ + F₂ → ZnF₂ + Br₂
Fluorine replaces bromine again. Another
single replacement reaction.
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Part B: Balance the chemical reactions and identify each type
1) CuCl₂ + H₂S → CuS + HCl
Left: Cu=1, Cl=2, H=2, S=1
Right: Cu=1, S=1, H=1, Cl=1 → Not balanced!
We need 2 HCl on right to match 2 Cl and 2 H.
Balanced:
CuCl₂ + H₂S → CuS + 2 HCl
Type: Two compounds swap parts →
double replacement
2) Ca + AgCl → CaCl₂ + Ag
Left: Ca=1, Ag=1, Cl=1
Right: Ca=1, Cl=2, Ag=1 → Cl not balanced
Need 2 AgCl on left to get 2 Cl, which means 2 Ag on right.
Balanced:
Ca + 2 AgCl → CaCl₂ + 2 Ag
Type: Element replaces another in compound →
single replacement
3) C₄H₈ + O₂ → CO₂ + H₂O
Left: C=4, H=8, O=?
Right: C=1, H=2, O=3 (from CO₂ and H₂O) → Need to balance
Start with C: put 4 in front of CO₂ → now C=4
H: 8 on left → need 4 H₂O on right (since each has 2 H) → H=8
Now O: Right side = 4×2 (from CO₂) + 4×1 (from H₂O) = 8 + 4 = 12 O atoms
So left needs 6 O₂ (since each O₂ has 2 O) → 6×2=12
Balanced:
C₄H₈ + 6 O₂ → 4 CO₂ + 4 H₂O
Type: Hydrocarbon + oxygen → CO₂ + H₂O →
combustion
4) PbSO₄ + AgNO₃ → Ag₂SO₄ + Pb(NO₃)₂
Left: Pb=1, S=1, O=4+3=7? Wait — let’s count properly.
PbSO₄: Pb=1, S=1, O=4
AgNO₃: Ag=1, N=1, O=3
Right: Ag₂SO₄: Ag=2, S=1, O=4
Pb(NO₃)₂: Pb=1, N=2, O=6
So total right: Ag=2, S=1, O=4+6=10, Pb=1, N=2
Left: To get 2 Ag, need 2 AgNO₃ → gives 2 Ag, 2 N, 6 O
Plus PbSO₄: Pb=1, S=1, O=4 → total O = 6+4=10 → matches!
Balanced:
PbSO₄ + 2 AgNO₃ → Ag₂SO₄ + Pb(NO₃)₂
Type: Swap of ions →
double replacement
5) Li + N₂ → Li₃N
Left: Li=1, N=2
Right: Li=3, N=1 → Not balanced
Need even number of N on right → try 2 Li₃N → Li=6, N=2
Then left needs 6 Li and 1 N₂
Balanced:
6 Li + N₂ → 2 Li₃N
Type: Two elements combine to form one compound →
synthesis (also called combination)
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Final Answer:
Part A:
1) Combustion
2) Double Replacement
3) Single Replacement
4) Decomposition
5) Single Replacement
Part B:
1) CuCl₂ + H₂S → CuS + 2 HCl — Double Replacement
2) Ca + 2 AgCl → CaCl₂ + 2 Ag — Single Replacement
3) C₄H₈ + 6 O₂ → 4 CO₂ + 4 H₂O — Combustion
4) PbSO₄ + 2 AgNO₃ → Ag₂SO₄ + Pb(NO₃)₂ — Double Replacement
5) 6 Li + N₂ → 2 Li₃N — Synthesis
Parent Tip: Review the logic above to help your child master the concept of reaction types worksheet.