Balance the following equation:

CaO+P2O5 = Ca3(PO4)2
Select the coefficient that would go in front of Ca3(PO4)2

1 answer

To balance the equation:

  1. Start with the unbalanced equation: \[ \text{CaO} + \text{P}_2\text{O}_5 \rightarrow \text{Ca}_3(\text{PO}_4)_2 \]

  2. Count the number of each type of atom on both sides of the equation:

    • For \(\text{Ca}_3(\text{PO}_4)_2\):
      • Calcium (Ca): 3
      • Phosphorus (P): 2
      • Oxygen (O): 8 (4 from PO4 * 2)
  3. We need 3 calcium (Ca) from CaO, which leads to: \[ 3 \text{CaO} \] This gives us 3 calcium.

  4. Now we consider phosphorus (P). We have 2 phosphorus in \(\text{Ca}_3(\text{PO}_4)_2\) and need one \(\text{P}_2\text{O}_5\): \[ 1 \text{P}_2\text{O}_5 \]

  5. Now, let's check the balance of oxygen. We have:

    • From \(3 \text{CaO}\): \(3 \times 1 = 3\) oxygen
    • From \(1 \text{P}_2\text{O}_5\): \(5\) oxygen
    • Total oxygen on the left: \(3 + 5 = 8\)
  6. Now consider the right side:

    • From \(\text{Ca}_3(\text{PO}_4)_2\): \(8\) oxygen
  7. Each side now has:

    • Ca: 3
    • P: 2
    • O: 8

Thus, the balanced equation is: \[ 3 \text{CaO} + 1 \text{P}_2\text{O}_5 \rightarrow 1 \text{Ca}_3(\text{PO}_4)_2 \]

The coefficient in front of \(\text{Ca}_3(\text{PO}_4)_2\) is 1.