Question

1.For the reaction P4 O10(s) + 6H2O(l) → 4H3PO4(aq), what mass of P

Answer 1

P₄O₁₀ + 6H₂O → 4H₃PO₄
The equation shows us that the molar ratio of
P₄O₁₀ : 6H₂O = 1:6

We also know that one mole of a substance contains 6.02 x 10²³ particles. We can use this to calculate the moles of water.
moles(H₂O) = (5.51 x 10²³) / (6.02 x 10²³)
= 0.92 mole
That means moles of P₄O₁₀ = 0.92 / 6
= 0.15

Each mole of P₄O₁₀ contains 4 moles of P. 
moles(P) = 4 x 0.15 = 0.6 mol
Mr of P = 207 grams per mol
Mass of P = 207 x 0.6
= 124.2 grams

Answer 2

$\boxed{{\text{18}}{\text{.582 g}}}$ of P is consumed if ${\text{5}}{\text{.51}}\times{\text{1}}{{\text{0}}^{{\text{23}}}}{\text{ molecules}}$ of ${{\text{H}}_{\text{2}}}{\text{O}}$ is consumed in the reaction ${{\text{P}}_4}{{\text{O}}_{10}}\left(s\right)+6{{\text{H}}_{\text{2}}}{\text{O}}\left(l\right)\to3{{\text{H}}_{\text{3}}}{\text{P}}{{\text{O}}_4}\left({aq}\right)$

Further Explanation:

Stoichiometry of a reaction is used to determine the amount of species present in the reaction by the relationship between the reactants and products. It can be used to determine the moles of a chemical species when the moles of other chemical species present in the reaction is given.

Consider the general reaction,

${\text{A}}+2{\text{B}}\to3{\text{C}}$

Here,

A and B are reactants.

C is the product.

One mole of A reacts with two moles of B to produce three moles of C. The stoichiometric ratio between A and B is 1:2, the stoichiometric ratio between A and C is 1:3 and the stoichiometric ratio between B and C is 2:3.

The given reaction is,

${{\text{P}}_4}{{\text{O}}_{10}}\left(s\right)+6{{\text{H}}_{\text{2}}}{\text{O}}\left(l\right)\to3{{\text{H}}_{\text{3}}}{\text{P}}{{\text{O}}_4}\left({aq}\right)$

One mole of ${{\text{P}}_4}{{\text{O}}_{10}}$  reacts with six moles of ${{\text{H}}_{\text{2}}}{\text{O}}$ to produce three moles of ${{\text{H}}_{\text{3}}}{\text{P}}{{\text{O}}_4}$ . So the stoichiometric ratio between ${{\text{P}}_4}{{\text{O}}_{10}}$ and ${{\text{H}}_{\text{2}}}{\text{O}}$ is 1:6.

According to Avogadro law, one mole of any substance contains ${\text{6}}{\text{.022}}\times{\text{1}}{{\text{0}}^{{\text{23}}}}$ molecules.

So the number of moles of water is calculated as follows:

$\align{{\text{Number of moles of water}}{\bf&{=}}\left( {{\text{5}}{\text{.51}}\times{\text{1}}{{\text{0}}^{{\text{23}}}}{\text{ molecules}}} \right)\left({\frac{{{\text{1 mol}}}}{{{\text{6}}{\text{.022}}\times{\text{1}}{{\text{0}}^{{\text{23}}}}{\text{ molecules}}}}}\right)\cr&={\text{0}}{\text{.914978}}\;{\text{mol}}\cr&\approx{\bf{0}}{\bf{.92}}\;{\bf{mol}}\cr}$

According to the stoichiometry of the reaction, 1 mole of ${{\text{P}}_4}{{\text{O}}_{10}}$ reacts with 6 moles of ${{\text{H}}_{\text{2}}}{\text{O}}$ to produce three moles of ${{\text{H}}_{\text{3}}}{\text{P}}{{\text{O}}_4}$ . So the number of moles of ${{\text{P}}_4}{{\text{O}}_{10}}$ formed by 0.92 moles of ${{\text{H}}_{\text{2}}}{\text{O}}$ is calculated as follows:

$\align{{\text{Moles of }}{{\text{P}}_4}{{\text{O}}_{10}}{\bf&{=}}\left({\frac{{{\text{0}}{\text{.92 mol}}}}{6}}\right)\cr&=0.1533\;{\text{mol}}\cr&\approx 0.15\;{\text{mol}}\cr}$

1 mole of ${{\text{P}}_4}{{\text{O}}_{10}}$ consists of 4 moles of P. So the moles of P can be calculated as follows:

$\align{{\text{Moles of P}}{\bf&{=}}\left({0.15\;{\text{mol}}}\right)\times4\cr&={\text{0}}{\text{.60 mol}}\cr}$

The formula to calculate the mass of P is as follows:

${\text{Mass of P}}=\left({{\text{Moles of P}}}\right)\left({{\text{Molar mass of P}}}\right)$           …… (1)

The number of moles of P is 0.60 mol.

The molar mass of P is 30.97 g/mol.

Substitute these values in equation (1).

$\align{{\text{Mass of P}}&=\left({{\text{0}}{\text{.60 mol}}}\right)\left({\frac{{{\text{30}}{\text{.97 g}}}}{{{\text{1 mol}}}}}\right)\cr&={\bf{18}}{\bf{.582 g}}\cr}$

Learn more:

1. How many moles of Cl are present in 8 moles of ${\text{CC}}{{\text{l}}_4}$ ? brainly.com/question/3064603

2. Calculate the moles of ions in HCl solution: brainly.com/question/5950133

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Mole concept

Keywords: stoichiometry, P4O10, H2O, H3PO4, A, B, C, P, moles of P, Avogadro law, molecules, 0.60 mol, 0.15 mol, molar mass, number of moles, 18.582 g, 30.97 g/mol.