Question

p₂o₃ + 3h₂o → 2h₃po₃
how many grams of diphosphorus trioxide, p₂o₃, are required to react completely with 4.0 moles h₂o?
molar mass p₂o₃: 109.94 g/mol
? g p₂o₃

Explanation:

Step1: Determine the mole ratio

From the balanced equation \(P_{2}O_{3}+3H_{2}O
ightarrow 2H_{3}PO_{3}\), the mole ratio of \(P_{2}O_{3}\) to \(H_{2}O\) is \(1:3\).

Step2: Calculate moles of \(P_{2}O_{3}\)

Given \(n(H_{2}O) = 4.0\space mol\). Using the mole ratio \(\frac{n(P_{2}O_{3})}{n(H_{2}O)}=\frac{1}{3}\), so \(n(P_{2}O_{3})=\frac{1}{3}\times n(H_{2}O)\).
\(n(P_{2}O_{3})=\frac{1}{3}\times4.0\space mol=\frac{4}{3}\space mol\)

Step3: Calculate mass of \(P_{2}O_{3}\)

Use the formula \(m = n\times M\), where \(M(P_{2}O_{3})=109.94\space g/mol\) and \(n(P_{2}O_{3})=\frac{4}{3}\space mol\)
\(m(P_{2}O_{3})=\frac{4}{3}\space mol\times109.94\space g/mol\)
\(m(P_{2}O_{3})\approx146.59\space g\)

Answer:

\(146.59\space g\)