Question

balance the below equations by adding appropriate coefficients
a. C2H4+O2~CO2+H2O

Answer 1

To balance the combustion reaction of ethylene (\( C_2H_4 \)) with oxygen (\( O_2 \)) producing carbon dioxide (\( CO_2 \)) and water (\( H_2O \)), we can follow these steps:

1. Write the unbalanced equation:
\[
C_2H_4 + O_2 \rightarrow CO_2 + H_2O
\]

2. Count the number of each type of atom on both sides:
- Reactants:
- C: 2
- H: 4
- O: 2 (from \( O_2 \))
- Products:
- C: 1 (from \( CO_2 \))
- H: 2 (from \( H_2O \))
- O: 3 (1 from \( CO_2 \) and 1 from \( H_2O \))

3. Now, let's balance carbon (C) first. Since there are 2 carbons in \( C_2H_4 \), we need 2 \( CO_2 \) molecules:
\[
C_2H_4 + O_2 \rightarrow 2 CO_2 + H_2O
\]

4. Next, balance hydrogen (H). There are 4 hydrogens in \( C_2H_4 \), so we need 2 water molecules:
\[
C_2H_4 + O_2 \rightarrow 2 CO_2 + 2 H_2O
\]

5. Now, count the number of oxygen atoms. On the right side:
- From \( 2 CO_2 \), there are \( 2 \times 2 = 4 \) oxygen atoms.
- From \( 2 H_2O \), there are \( 2 \times 1 = 2 \) oxygen atoms.
- Total = \( 4 + 2 = 6 \) oxygens.

6. Now we can balance the oxygen on the left side. We need a total of 6 oxygen atoms, and since each \( O_2 \) molecule provides 2 oxygen atoms, we need 3 \( O_2 \) molecules:
\[
C_2H_4 + 3 O_2 \rightarrow 2 CO_2 + 2 H_2O
\]

7. Finally, the balanced equation is:
\[
\boxed{C_2H_4 + 3 O_2 \rightarrow 2 CO_2 + 2 H_2O}
\]