Answer:
5974 g of Na₃P
Explanation:
We determine the reaction:
2Na₃P + 3SrO → 3Na₂O + Sr₃P₂
2 moles of sodium phosphide react to 3 moles of strontium oxide to produce 3 moles of sodium oxide and 1 mol of strontium phosphide.
We know that 1 mol of anything contains 6.02×10²³ formula units, so:
5.4×10²⁵ formula units . 1 mol/6.02×10²³ formula units = 89.7 moles
This is the amount we have, initially for SrO.
Ratio is 3:2. 3 moles of SrO react to 2 Na₃P
Then 89.7 moles of SrO may react to (89.7 . 2) /3 = 59.8 moles of Na₃P
We convert the moles to mass (mass . molecular weight)
59.8 mol . 99.9 g /mol = 5974 g