Question

Mr(H3PO4) = 3 · Ar(H) + Ar(P) + 4 · Ar(O) = w (элемент) = (n · Ar(элемент) 100%) / Mr(зат); w(H) = n(H) · Ar(H) · 100% / Mr(H3PO4) = %; w(P) = n(P) · Ar(P) · 100% / Mr(H3PO4) = %; w(O) = n(O) · Ar(O) · 100% / Mr(H3PO4) = %;

Answer 1

Mr (H3PO4) = 3·Ar (H) + Ar (P) + 4·Ar (O) =  98

w (H) = n (H)·Ar (H) · 100% / Mr (H3PO4)=3,06%

w (P) = n (P)·Ar (P) · 100% / Mr (H3PO4)=31,63%

w (O) = n (O)·Ar (O) · 100% / Mr (H3PO4)=65,31%

Answer 2

To calculate the mass percentages of hydrogen (H), phosphorus (P), and oxygen (O) in phosphoric acid (H₃PO₄), you can use the following formulas:

w(H) = n(H) * Ar(H) * 100% / Mr(H₃PO₄) w(P) = n(P) * Ar(P) * 100% / Mr(H₃PO₄) w(O) = n(O) * Ar(O) * 100% / Mr(H₃PO₄)

Here are the values of atomic masses (Ar) for hydrogen (H), phosphorus (P), and oxygen (O):

Ar(H) = 1.0079 g/mol Ar(P) = 30.9738 g/mol Ar(O) = 15.999 g/mol

And the molar mass (Mr) of phosphoric acid (H₃PO₄) is:

Mr(H₃PO₄) = 3 * Ar(H) + Ar(P) + 4 * Ar(O)

Let's assume we have the following values for the moles of each element in H₃PO₄:

n(H) = number of moles of hydrogen n(P) = number of moles of phosphorus n(O) = number of moles of oxygen

Substituting these values into the formulas, we can calculate the mass percentages:

w(H) = n(H) * Ar(H) * 100% / Mr(H₃PO₄) w(P) = n(P) * Ar(P) * 100% / Mr(H₃PO₄) w(O) = n(O) * Ar(O) * 100% / Mr(H₃PO₄)

Please provide the values of n(H), n(P), and n(O) to proceed with the calculations.