4P + 50_2 ---> 2P205

25.4g of P are used with excess 02 how many grams of p205 should theoretically form

I have no idea where to start im lost

To solve this problem, we'll use stoichiometry and the balanced chemical equation. The balanced equation for the reaction is:

4P + 5O2 → 2P2O5

The coefficients in the balanced equation tell us the molar ratios between the P and P2O5.

To find the number of moles of P2O5, we need to convert grams of P to moles of P using the molar mass of P, and then use the stoichiometric ratio to convert moles of P to moles of P2O5. Finally, we can convert moles of P2O5 back to grams of P2O5.

Here are the steps to solve the problem:

1. Determine the molar mass of P:
Phosphorus (P) has an atomic mass of 31 g/mol.

2. Convert grams of P to moles of P:
Divide the given mass (25.4 g) by the molar mass of P.

moles of P = 25.4 g P / 31 g/mol ≈ 0.819 mol P

3. Use the stoichiometric ratio to convert moles of P to moles of P2O5:
From the balanced equation, we see that 4 moles of P react to form 2 moles of P2O5.

Using the ratio: moles of P2O5 = 0.819 mol P × (2 mol P2O5 / 4 mol P) = 0.4095 mol P2O5

4. Convert moles of P2O5 to grams of P2O5:
Multiply the moles of P2O5 by the molar mass of P2O5.

grams of P2O5 = 0.4095 mol P2O5 × (141.94 g/mol) ≈ 58.13 g P2O5

Therefore, theoretically, approximately 58.13 grams of P2O5 should form when 25.4 grams of P reacts with excess O2.