On the Calculation of Phosphorus Content in Phosphoric Acid
Now I want to know the geometry of phosphorus content in one pound of phosphoric acid. For phosphoric acid, the chemical formula is $H_3PO_3 $.

The atomic weight of hydrogen ($H $) is about 1 dollar $, the atomic weight of phosphorus ($P $) is about 31 dollars $, and the atomic weight of oxygen ($O $) is about 16 dollars $.

The molecular weight of phosphoric acid $H_3PO_3 $is: 3 dollars\ times1 + 31 + 3\ times16 = 3 + 31 + 48 = 82 $.

In $H_3PO_3 $, the mass fraction of phosphorus is: $\ frac {31} {82} $.

If there is one pound of phosphorus, one pound is equal to 453.592 dollars $gram.

The amount of this pound of phosphorus is: $n =\ frac {m} {M} =\ frac {453.592g} {82g/mol}\ approx5.5316mol $.

The amount of phosphorus corresponds to the number of phosphorus atoms in phosphorus, which is also $5.5316mol $.

The mass of phosphorus is: $m_ {P} = n_ {P}\ times M_ {P} = 5.5316mol\ times31g/mol\ approx171.48g $.

Converted to pounds, 1 dollar $gram is equal to 0.00220462 dollars $pound, so the mass of phosphorus is $171.48g\ times0.00220462\ approx0.378 $pound.

From this, it can be seen that one pound of phosphorus contains about 0.378 dollars $pound of phosphorus.