Let's balance each chemical equation and classify them into their respective classes:
B. CH₄ (g) + H₂O (g) = CO (g) + H₂ (g)
Balanced Equation: To balance the equation, we can write: \[ \text{CH}_4 (g) + \text{H}_2\text{O} (g) \rightarrow \text{CO} (g) + 3\text{H}_2 (g) \] (1 molecule of CH₄ reacts with 1 molecule of H₂O to produce 1 molecule of CO and 3 molecules of H₂)
Classification: This is a decomposition reaction since methane is breaking down into carbon monoxide and hydrogen.
C. FeS (s) + HCl (aq) = FeCl₂ (aq) + H₂S (g)
Balanced Equation: This equation is already balanced: \[ \text{FeS} (s) + 2\text{HCl} (aq) \rightarrow \text{FeCl}_2 (aq) + \text{H}_2\text{S} (g) \]
Classification: This is a single replacement reaction (or single displacement reaction) since one of the elements (Fe) is replaced by another (H).
D. C₂H₆ (g) + O₂ (g) = CO₂ (g) + H₂O (g)
Balanced Equation: Balancing this combustion reaction: \[ 2\text{C}_2\text{H}_6 (g) + 7\text{O}_2 (g) \rightarrow 4\text{CO}_2 (g) + 6\text{H}_2\text{O} (g) \]
Classification: This is a combustion reaction since it involves the burning of a hydrocarbon (ethane) in oxygen.
E. NO (g) + O₂ (g) = NO₂ (g)
Balanced Equation: To balance this reaction: \[ 2\text{NO} (g) + \text{O}_2 (g) \rightarrow 2\text{NO}_2 (g) \]
Classification: This is a synthesis reaction (or combination reaction) because nitrogen monoxide and oxygen combine to form nitrogen dioxide.
Summary:
- B: Decomposition reaction (Balanced: \( \text{CH}_4 + \text{H}_2\text{O} \rightarrow \text{CO} + 3\text{H}_2 \))
- C: Single replacement reaction (Balanced: \( \text{FeS} + 2\text{HCl} \rightarrow \text{FeCl}_2 + \text{H}_2\text{S} \))
- D: Combustion reaction (Balanced: \( 2\text{C}_2\text{H}_6 + 7\text{O}_2 \rightarrow 4\text{CO}_2 + 6\text{H}_2\text{O} \))
- E: Synthesis reaction (Balanced: \( 2\text{NO} + \text{O}_2 \rightarrow 2\text{NO}_2 \))