Question

Among the following equations, which one is in a balanced state?
A. 2 C3H8 + 4 O2 → 2 CO2 + 4 H2O
B. C3H8 + 5 O2 → 3 CO2 + 4 H2O
C. C3H8 + 11 O2 → 3 CO2 + 8 H2O
D. C3H8 + 3 O2 → CO2 + H2O

Answer 1

To determine which equation is balanced, we need to count the number of atoms of each element on both sides of the reaction for each option.

**Option A: 2 C3H8 + 4 O2 → 2 CO2 + 4 H2O**

- Reactants:
- Carbon (C): 2 * 3 = 6
- Hydrogen (H): 2 * 8 = 16
- Oxygen (O): 4 * 2 = 8

- Products:
- Carbon (C): 2 * 1 = 2
- Hydrogen (H): 4 * 2 = 8
- Oxygen (O): 2 * 2 + 4 * 1 = 4 + 4 = 8

**Count matching: Incorrect** (6 C, 16 H, 8 O not matching)

**Option B: C3H8 + 5 O2 → 3 CO2 + 4 H2O**

- Reactants:
- Carbon (C): 3
- Hydrogen (H): 8
- Oxygen (O): 5 * 2 = 10

- Products:
- Carbon (C): 3 * 1 = 3
- Hydrogen (H): 4 * 2 = 8
- Oxygen (O): 3 * 2 + 4 * 1 = 6 + 4 = 10

**Count matching: Correct** (3 C, 8 H, 10 O matching)

**Option C: C3H8 + 11 O2 → 3 CO2 + 8 H2O**

- Reactants:
- Carbon (C): 3
- Hydrogen (H): 8
- Oxygen (O): 11 * 2 = 22

- Products:
- Carbon (C): 3 * 1 = 3
- Hydrogen (H): 8 * 2 = 16
- Oxygen (O): 3 * 2 + 8 * 1 = 6 + 8 = 14

**Count matching: Incorrect** (3 C, 8 H, 22 O not matching)

**Option D: C3H8 + 3 O2 → CO2 + H2O**

- Reactants:
- Carbon (C): 3
- Hydrogen (H): 8
- Oxygen (O): 3 * 2 = 6

- Products:
- Carbon (C): 1
- Hydrogen (H): 2
- Oxygen (O): 2 + 1 = 3

**Count matching: Incorrect** (3 C, 8 H, 6 O not matching)

After reviewing all options, the only balanced equation is:

**B. C3H8 + 5 O2 → 3 CO2 + 4 H2O**