What is the maximum amount in moles of p2o5 that can theoretically be made from 186 g of p4 and excess oxygen?

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P4(s) + 10 Cl2(g) → 4 PCl5(g)

P4 + 5 O2 → 2 P2O5

(186 g P4) / (123.8950 g/mol) x (2/1) x (141.9447 g/mol) = 426 g P2O5

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BarrettArcher BarrettArcher · Answer 2 · 2019-03-19T08:41:07-04:00

Answer : The maximum amount in moles of \(P_2O_5\) is, 3 moles

Solution : Given,

Mass of \(P_4\) = 186 g

Molar mass of \(P_4\) = 123.88 g/mole

First we have to calculate the moles of \(P_4\).

\(\text{Moles of }P_4=\frac{\text{Mass of }P_4}{\text{Molar mass of }P_4}=\frac{186g}{123.88g/mole}=1.50moles\)

Now we have to calculate the moles of \(P_2O_5\).

The balanced chemical reaction will be,

\(P_4+5O_2\rightarrow 2P_2O_5\)

From the balanced reaction, we conclude that

As, 1 mole of \(P_4\) react to give 2 moles of \(P_2O_5\)

So, 1.50 moles of \(P_4\) react to give \(2\times 1.50=3moles\) of \(P_2O_5\)

Therefore, the maximum amount in moles of \(P_2O_5\) is, 3 moles