Which of the following reactions isnot correct according to the law of conservation of mass?

Options

A. `2Mg(s)+O_(2)(g)rarr2MgO(s)`
B. `C_(3)H_(6)(g)+O_(2)(g)rarrCO_(2)(g)+H_(2)O(g)`
C. `P_(4)(s)+5O_(2)(g)rarrP_(4)O_(10)(s)`
D. `CH_(4)(g)+2O_(2)(g)rarrCO_(2)(g)+2H_(2)O(g)`

Explanation

To determine which of the following reactions is not correct according to the law of conservation of mass, we will analyze each reaction to see if the mass of the reactants equals the mass of the products.

### Step 1: Analyze Option A
**Reaction:** 2 moles of Mg + O2 → 2 moles of MgO

- **Reactants:**
- Magnesium (Mg): 2 moles
- Oxygen (O2): 1 mole (which is 2 atoms of oxygen)
...