Propane (C3H8) is burned in an oxygen atmosphere with 10% deficit oxyg...
C3H8 + xO2 → aCO2 + bH2O
Carbon balance :
a = 3
hydrogen balance:
2b = 8 → b = 4
Oxygen balance:
2x = 2a + b
For chemically correct or stoichiometric burning, no. of moles of O2 required are = 5.
As it is burnt with 10% deficient oxygen, it will generate CO.
The new equation is
C3H8 + 0.9 x 5O2 → aCO2 + bCO + cH2O
Carbon balance:
a + b = 3
Hydrogen balance:
2c = 8 → c = 4
Oxygen balance:
2a + b + c = 0.9 x 5 x 2 = 9
2a + b + c = 9
⇒ 2a + b + 4 = 9 ⇒ 2a + b = 5 … (1)
a + b = 3 … (2)
By solving (1) & (2)
a = 2 & b = 1
in the exhaust products the no. of moles of CO are 1.% by volume of CO in exhaust.
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Propane (C3H8) is burned in an oxygen atmosphere with 10% deficit oxyg...
Given Information:
- Propane (C3H8) is burned in an oxygen atmosphere.
- The oxygen is present in a 10% deficit with respect to the stoichiometric requirement.
- No hydrocarbons are present in the products.
To Find:
The volume percentage of CO in the products.
Solution:
1. Balanced Chemical Equation:
The balanced chemical equation for the combustion of propane is as follows:
C3H8 + 5O2 -> 3CO2 + 4H2O
2. Stoichiometric Calculation:
The stoichiometric ratio between propane and carbon monoxide (CO) can be obtained from the balanced chemical equation.
From the equation, we can see that 3 moles of CO are formed for every mole of propane burned.
3. Calculation of Oxygen Deficit:
The oxygen deficit is given as 10% with respect to the stoichiometric requirement.
To calculate the oxygen deficit, we need to find the stoichiometric requirement of oxygen for burning propane.
From the balanced chemical equation, we can see that 1 mole of propane requires 5 moles of oxygen.
So, for burning propane, the stoichiometric requirement of oxygen is 5 times the moles of propane.
The oxygen deficit is 10% of the stoichiometric requirement, which means the actual amount of oxygen available is 90% of the stoichiometric requirement.
Therefore, the oxygen deficit is 0.9 times the stoichiometric requirement.
4. Calculation of CO Formation:
Since there is an oxygen deficit, the reaction will not go to completion, and some propane will be left unreacted.
To calculate the amount of CO formed, we need to consider the propane that reacts completely and the propane that remains unreacted due to the oxygen deficit.
Let's assume the stoichiometric requirement of propane as 'x' moles.
The amount of propane that reacts completely = x moles
The amount of propane that remains unreacted = 0.1x moles (10% deficit)
From the balanced chemical equation, we know that 3 moles of CO are formed for every mole of propane.
So, the amount of CO formed from the propane that reacts completely = 3x moles
The amount of CO formed from the propane that remains unreacted = 3 * 0.1x = 0.3x moles
Therefore, the total moles of CO formed = 3x + 0.3x = 3.3x moles
5. Calculation of Volume Percentage:
To calculate the volume percentage of CO, we need to compare the moles of CO with the total moles of products.
From the balanced chemical equation, we know that the total moles of products formed are 3 moles of CO2 and 4 moles of H2O for every mole of propane.
So, the total moles of products formed = 3 moles of CO2 + 4 moles of H2O = 7 moles
The volume percentage of CO = (moles of CO / total moles of products) * 100
Substituting the values, the volume percentage of CO = (3.3x / 7x) * 100 = 47