1.The equation from the combustion of hexane is:
C6H14(g)+19/2 O2(g) -(arrow sign) 6CO2(g)+7H2O(g)
Calculate the number of moles of
a) CO2 produced in the combustion of 1.50 moles of hexane
b) H2O produced in the combustion of 0.25 moles of hexane
c) O2 consumed in the combustion of 0.40 moles of hexane
The Correct Answer and Explanation is :
Solution:
The balanced chemical equation for the combustion of hexane is:
[
C_6H_{14}(g) + \frac{19}{2} O_2(g) \rightarrow 6 CO_2(g) + 7 H_2O(g)
]
This equation tells us the molar ratio between the reactants and products:
- 1 mole of C₆H₁₄ produces 6 moles of CO₂.
- 1 mole of C₆H₁₄ produces 7 moles of H₂O.
- 1 mole of C₆H₁₄ consumes ( \frac{19}{2} = 9.5 ) moles of O₂.
(a) Moles of CO₂ produced from 1.50 moles of hexane
Using the molar ratio:
[
\text{Moles of CO₂} = (1.50 \text{ moles C₆H₁₄}) \times \frac{6 \text{ moles CO₂}}{1 \text{ mole C₆H₁₄}}
]
[
= 9.00 \text{ moles CO₂}
]
(b) Moles of H₂O produced from 0.25 moles of hexane
Using the molar ratio:
[
\text{Moles of H₂O} = (0.25 \text{ moles C₆H₁₄}) \times \frac{7 \text{ moles H₂O}}{1 \text{ mole C₆H₁₄}}
]
[
= 1.75 \text{ moles H₂O}
]
(c) Moles of O₂ consumed in the combustion of 0.40 moles of hexane
Using the molar ratio:
[
\text{Moles of O₂} = (0.40 \text{ moles C₆H₁₄}) \times \frac{9.5 \text{ moles O₂}}{1 \text{ mole C₆H₁₄}}
]
[
= 3.80 \text{ moles O₂}
]
Explanation:
The calculations above rely on stoichiometry, which is the method of using balanced chemical equations to determine the quantitative relationships between reactants and products.
In every chemical reaction, substances combine in fixed ratios determined by their molecular structure and bonding. The combustion of hexane follows a specific molar proportion:
- 1 mole of hexane (C₆H₁₄) combusts with 9.5 moles of oxygen.
- Each mole of hexane produces 6 moles of CO₂ and 7 moles of water.
These values come directly from the coefficients in the balanced equation.
For part (a), the given moles of hexane are multiplied by the molar ratio (6 CO₂ per 1 C₆H₁₄), resulting in 9.00 moles of CO₂.
For part (b), a similar approach is used with water, applying the 7:1 ratio to 0.25 moles of hexane to get 1.75 moles of H₂O.
For part (c), the oxygen consumption is calculated based on the 9.5:1 molar ratio. Multiplying this by 0.40 moles of hexane results in 3.80 moles of O₂.
Understanding these concepts is crucial in chemistry, as they are widely used in energy calculations, fuel efficiency analysis, and reaction predictions in industries such as automotive, aerospace, and environmental sciences.