Question

directions: balance each chemical reaction below and then classify the chemical reactions as synthesis (s), decomposition (d), single-displacement (sd), double-displacement (dd), combustion (c), or acid-base (ab).

1. hbr + mg(oh)₂ → mgbr₂ + h₂o =
2. pbbr₂ + hcl → hbr + pbcl₂ =
3. cobr₃ + caso₄ → cabr₂ + co₂(so₄)₃ =
4. c₄h₁₂ + o₂ → co₂ + h₂o =
5. b₂o₃ + h₂o → h₃bo₃ =
6. h₂o → h₂ + o₂ =
7. c₂h₄ + o₂ → co₂ + h₂o =
8. mg + fe₂o₃ → mgo + fe =
9. h₃po₄ + ca(oh)₂ → ca₃(po₄)₂ + h₂o =
10. cl₂ + kbr → kcl + br₂ =
11. h₃aso₄ → as₂o₅ + h₂o =
12. s₈ + o₂ → so₃ =
13. bi(no₃)₃ + al₂(so₄)₃ → bi₂(so₄)₃ + al(no₃)₃ =
14. hgo → hg + o₂ =
15. p + o₂ → p₂o₃ =
16. hbr + ba(oh)₂ → babr₂ + h₂o =
17. fe + h₂o → fe₃o₄ + h₂ =

Explanation:

Step1: Recall reaction type definitions

• Synthesis: \(A + B

ightarrow AB\)

• Decomposition: \(AB

ightarrow A + B\)

• Single - Displacement: \(A+BC

ightarrow AC + B\)

• Double - Displacement: \(AB + CD

ightarrow AD+CB\)

• Combustion: \(C_xH_y+(x + \frac{y}{4})O_2

ightarrow xCO_2+\frac{y}{2}H_2O\)

• Acid - Base: \(H^+ + OH^-

ightarrow H_2O\) (a type of double - displacement where acid and base react)

Step2: Analyze each reaction

1. \(2HBr+Mg(OH)_2

ightarrow MgBr_2 + 2H_2O\) (Acid - Base, \(H^+\) from \(HBr\) reacts with \(OH^-\) from \(Mg(OH)_2\))

1. \(PbBr_2+2HCl

ightarrow 2HBr + PbCl_2\) (Double - Displacement)

1. \(2CoBr_3 + 3CaSO_4

ightarrow 3CaBr_2+Co_2(SO_4)_3\) (Double - Displacement)

1. \(C_4H_{12}+7O_2

ightarrow 4CO_2 + 6H_2O\) (Combustion)

1. \(B_2O_3+3H_2O

ightarrow 2H_3BO_3\) (Synthesis)

1. \(2H_2O

ightarrow 2H_2+O_2\) (Decomposition)

1. \(C_2H_4 + 3O_2

ightarrow 2CO_2+2H_2O\) (Combustion)

1. \(3Mg+Fe_2O_3

ightarrow 3MgO + 2Fe\) (Single - Displacement)

1. \(2H_3PO_4+3Ca(OH)_2

ightarrow Ca_3(PO_4)_2 + 6H_2O\) (Acid - Base)

1. \(Cl_2+2KBr

ightarrow 2KCl + Br_2\) (Single - Displacement)

1. \(2H_3AsO_4

ightarrow As_2O_5+3H_2O\) (Decomposition)

1. \(S_8+12O_2

ightarrow 8SO_3\) (Synthesis)

1. \(2Bi(NO_3)_3+Al_2(SO_4)_3

ightarrow Bi_2(SO_4)_3 + 2Al(NO_3)_3\) (Double - Displacement)

1. \(2HgO

ightarrow 2Hg+O_2\) (Decomposition)

1. \(4P + 3O_2

ightarrow 2P_2O_3\) (Synthesis)

1. \(2HBr+Ba(OH)_2

ightarrow BaBr_2+2H_2O\) (Acid - Base)

1. \(3Fe + 4H_2O

ightarrow Fe_3O_4+4H_2\) (Single - Displacement)

Answer:

1. AB
2. DD
3. DD
4. C
5. S
6. D
7. C
8. SD
9. AB
10. SD
11. D
12. S
13. DD
14. D
15. S
16. AB
17. SD