(a) To find the wet volumetric and gravimetric analysis of the products of combustion when the equivalence ratio (Φ) is 1.0, we need to consider the stoichiometry of the combustion reaction for propane (C₃H₈) and butane (C₄H₁₀).
The balanced combustion reaction for propane can be represented as:
C₃H₈ + (5/2)O₂ → 3CO₂ + 4H₂O
And the balanced combustion reaction for butane can be represented as:
C₄H₁₀ + (6.5)O₂ → 4CO₂ + 5H₂O
Since LPG is composed of 60% propane and 40% butane by volume, we can calculate the wet volumetric and gravimetric analysis based on these proportions.
Wet volumetric analysis:
For the wet volumetric analysis, we consider the volume of the products of combustion relative to the volume of the LPG consumed.
Propane (C₃H₈):
The stoichiometric coefficient of propane in the combustion reaction is 3. Therefore, for every mole of propane burned, we will have 3 moles of CO₂ and 4 moles of H₂O formed.
Butane (C₄H₁₀):
The stoichiometric coefficient of butane in the combustion reaction is 4. Therefore, for every mole of butane burned, we will have 4 moles of CO₂ and 5 moles of H₂O formed.
Considering the initial composition of 60% propane and 40% butane by volume, we can calculate the volumetric composition of the products of combustion:
Volumetric composition of CO₂:
(0.6 * 3) + (0.4 * 4) = 3.6
Volumetric composition of H₂O:
(0.6 * 4) + (0.4 * 5) = 4.6
Therefore, the wet volumetric analysis of the products of combustion is 3.6 parts CO₂ to 4.6 parts H₂O.
Wet gravimetric analysis:
For the wet gravimetric analysis, we consider the mass of the products of combustion relative to the mass of the LPG consumed.
Using the molar masses of the compounds involved in the combustion reaction:
Molar mass of CO₂ = 44 g/mol
Molar mass of H₂O = 18 g/mol
Gravimetric composition of CO₂:
(0.6 * 3 * 44 g/mol) + (0.4 * 4 * 44 g/mol) = 158.4 g
Gravimetric composition of H₂O:
(0.6 * 4 * 18 g/mol) + (0.4 * 5 * 18 g/mol) = 74.4 g
Therefore, the wet gravimetric analysis of the products of combustion is 158.4 grams CO₂ to 74.4 grams H₂O.
(b) The stoichiometric air to fuel ratio for LPG can be determined based on the balanced combustion equations for propane and butane.
For propane (C₃H₈):
C₃H₈ + (5/2)O₂ → 3CO₂ + 4H₂O
The stoichiometric coefficient for propane is 1, which means we need 5/2 moles of O₂ for every mole of propane.
For butane (C₄H₁₀):
C₄H₁₀ + (6.5)O₂ → 4CO₂ + 5H₂O