Question

What types of chemical reactions are the following?

Column A
1.
2 H2O → 2 H2 + O2

:
2 H2O → 2 H2 + O2

2.
2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

:
2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

3.
2 Na + Cl2 → 2 NaCl

:
2 Na + Cl2 → 2 NaCl

4.
4 AlBr3 + 3 O2 → 2 Al2O3 + 6 Br2

:
4 AlBr3 + 3 O2 → 2 Al2O3 + 6 Br2

5.
KCl + NaI → KI + NaCl

:
KCl + NaI → KI + NaCl

Column B
a. Single Replacement
b. Combustion
c. Double Replacement
d. Synthesis
e. Decomposition

Answer 1

Here are the classifications of the chemical reactions listed in Column A:

1. **2 H2O → 2 H2 + O2**:
- This is a **e. Decomposition** reaction, as water is broken down into hydrogen and oxygen gases.

2. **2 C2H6 + 7 O2 → 4 CO2 + 6 H2O**:
- This is a **b. Combustion** reaction, as ethane (C2H6) is combusted in the presence of oxygen to produce carbon dioxide and water.

3. **2 Na + Cl2 → 2 NaCl**:
- This is a **d. Synthesis** reaction, as sodium and chlorine are combining to form sodium chloride.

4. **4 AlBr3 + 3 O2 → 2 Al2O3 + 6 Br2**:
- This is a **e. Decomposition** reaction. Aluminum bromide is decomposed in the presence of oxygen to form aluminum oxide and bromine.

5. **KCl + NaI → KI + NaCl**:
- This is a **c. Double Replacement** reaction, as the ions in the reactants exchange partners to form the products.

Putting those answers together:

- 1: **e. Decomposition**
- 2: **b. Combustion**
- 3: **d. Synthesis**
- 4: **e. Decomposition**
- 5: **c. Double Replacement**