To balance a chemical equation, the number of atoms of each element must be equal on both sides(reactant and product sides) of the equation.
Here is a step-by-step process to balance the equation “C3H8O + O2 → CO2 + H2O”:
Steps to balance the equation “C3H8O + O2 → CO2 + H2O”
Step 1: Write the unbalanced equation: ⇒ C3H8O + O2 → CO2 + H2O |
Step 2: Count the number of atoms of each element on both sides of the equation. Look at the number of atoms of each element on the reactant side (left side) and compare it to the number of atoms of that element on the product side (right side). C3H8O + O2 → CO2 + H2O | Reactant side | Product side | Carbon: 3 | Carbon: 1 | Hydrogen: 8 | Hydrogen: 2 | Oxygen: 3 | Oxygen: 3 |
As we see, on the reactant side, there is an odd number coefficient (Carbon: 3 and Oxygen: 3), so it will be difficult to balance the odd number compared to the even number coefficient. So, just multiply the C3H8O by the 2 on the reactant side. The new equation will be – ⇒ 2C3H8O + O2 → CO2 + H2O Now compare the number of atoms on the reactant side to the product side for the above reaction. 2C3H8O + O2 → CO2 + H2O | Reactant side | Product side | Carbon: 6 | Carbon: 1 | Hydrogen: 16 | Hydrogen: 2 | Oxygen: 4 | Oxygen: 3 |
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Step 3: Balance the Carbon atoms In the above equation, we can see that we have 6 Carbon atoms on the reactant side and 1 Carbon atom on the product side. So, to balance the number of Carbon atoms, we need to multiply the number of CO2 on the product side by 6. The new equation will be: ⇒ 2C3H8O + O2 → 6CO2 + H2O Again compare the number of atoms on the reactant side to the product side. 2C3H8O + O2 → 6CO2 + H2O | Reactant side | Product side | Carbon: 6 | Carbon: 6 | Hydrogen: 16 | Hydrogen: 2 | Oxygen: 4 | Oxygen: 13 (12 + 1) |
[∴ Carbon atoms balanced in the above equation] |
Step 4: Balance the Hydrogen atoms Similarly, according to the above equation(step 3), we have 16 Hydrogen atoms on the reactant side and 2 Hydrogen atoms on the product side. So, to balance the number of Hydrogen atoms, we need to multiply the number of H2O on the product side by 8. Now the equation looks like this: ⇒ 2C3H8O + O2 → 6CO2 + 8H2O Again compare the number of atoms on the reactant side to the product side. 2C3H8O + O2 → 6CO2 + 8H2O | Reactant side | Product side | Carbon: 6 | Carbon: 6 | Hydrogen: 16 | Hydrogen: 16 | Oxygen: 4 | Oxygen: 20 (12 + 8) |
[∴ Hydrogen atom balanced in this equation] |
Step 5: Balance the Oxygen atoms Now we have to balance the Oxygen atoms, according to the Step 4 equation, we have 4 Oxygen atoms on the reactant side and (12 + 8 = 20) Oxygen atoms on the product side. What we do here is that multiply the O2 on the reactant side by 9, this will give us 18 oxygen + 2 oxygen we have already in 2C3H8O, so the total will be 20 oxygen on the reactant side. The final balanced equation will be: ∴ 2C3H8O + 9O2 → 6CO2 + 8H2O Again compare the number of atoms on the reactant side to the product side. 2C3H8O + 9O2 → 6CO2 + 8H2O | Reactant side | Product side | Carbon: 6 | Carbon: 6 | Hydrogen: 16 | Hydrogen: 16 | Oxygen: 20 (2 + 18) | Oxygen: 20 (12 + 8) |
[∴ All the atoms balanced in this equation] |
So, the balance equation of the reaction: C3H8O + O2 → CO2 + H2O is – ⇒ 2C3H8O + 9O2 → 6CO2 + 8H2O [Answer] 2C3H8O + 9O2 → 6CO2 + 8H2O | Reactant side | Product side | Carbon: 6 | Carbon: 6 | Hydrogen: 16 | Hydrogen: 16 | Oxygen: 20 | Oxygen: 20 |
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In this step-by-step solution, we have balanced the equation: (C3H8O + O2 → CO2 + H2O) by adjusting the coefficient of each element, ensuring that the number of atoms of each element is the same on both sides of the equation.
Here check the balancing equation (C3H8O + O2 → CO2 + H2O) video to clear your doubt –
References
- ChemicalAid. “Equation Balancer.” [Online]. Available: https://www.chemicalaid.com/tools/equationbalancer.php?equation=C3H8O+%2B+O2+%3D+CO2+%2B+H2O&hl=en. [Accessed: 26-Jan-2023].