Give the balanced equation for the combustion of liquid hexane (C6H14) in the presence of oxygen gas
The Correct Answer and Explanation is:
The combustion of liquid hexane (C₆H₁₄) in the presence of oxygen (O₂) is a chemical reaction where hexane reacts with oxygen to produce carbon dioxide (CO₂) and water (H₂O). The balanced equation for this combustion reaction is:
2 C₆H₁₄(l) + 19 O₂(g) → 12 CO₂(g) + 14 H₂O(g)
Explanation:
- Combustion reaction overview: Combustion is a reaction between a substance and oxygen, producing energy (usually in the form of heat and light). In the case of hexane, which is a hydrocarbon, the products of complete combustion are always carbon dioxide (CO₂) and water (H₂O).
- Step-by-step balancing:
- Carbon atoms: Hexane (C₆H₁₄) has 6 carbon atoms, so we need to produce 6 CO₂ molecules to balance the carbon atoms. This gives us: C6H14→6CO2C_6H_{14} \rightarrow 6CO_2C6H14→6CO2
- Hydrogen atoms: Hexane has 14 hydrogen atoms. In water (H₂O), each molecule contains 2 hydrogen atoms, so to balance the hydrogen atoms, we need 7 H₂O molecules (since 7×2=147 \times 2 = 147×2=14). C6H14→7H2OC_6H_{14} \rightarrow 7H_2OC6H14→7H2O
- Oxygen atoms: Now, we count the oxygen atoms. On the product side, 6 CO₂ molecules contribute 12 oxygen atoms, and 7 H₂O molecules contribute 7 oxygen atoms, for a total of 19 oxygen atoms. Therefore, we need 19 O₂ molecules on the reactant side: O2→19OO_2 \rightarrow 19OO2→19O
- Final balanced equation: The coefficients now balance the number of atoms on both sides, resulting in the final balanced equation: 2C6H14+19O2→12CO2+14H2O2 C_6H_{14} + 19 O_2 \rightarrow 12 CO_2 + 14 H_2O2C6H14+19O2→12CO2+14H2O
This equation shows that two molecules of hexane react with nineteen molecules of oxygen to produce twelve molecules of carbon dioxide and fourteen molecules of water. It follows the law of conservation of mass, meaning the number of atoms of each element is the same on both sides of the equation.
