The phophorus pentoxide used to produce phosphoric acid for cola soft drinks is prepared by nurning phosphorus in oxygen.

(a)what is the limiting reactant when 0.200 mol of P4 and and 0.200 mol of O2 react according to P4 + 5O2 ? P4O10

(b)Calculate the percent yield if 10.0 g of P4O10 is isolated from the reaction.

Respuesta :

Answer : The percent yield of [tex]P_4O_{10}[/tex] is, 87.7 %

Solution : Given,

Moles of [tex]P_4[/tex] = 0.200 mole

Moles of [tex]O_2[/tex] = 0.200 mole

Molar mass of [tex]P_4O_{10}[/tex] = 283.9 g/mole

First we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

[tex]P_4+5O_2\rightarrow P_4O_{10}[/tex]

From the balanced reaction we conclude that

As, 5 mole of [tex]O_2[/tex] react with 1 mole of [tex]P_4[/tex]

So, 0.200 moles of [tex]O_2[/tex] react with [tex]\frac{0.200}{5}=0.04[/tex] moles of [tex]P_4[/tex]

From this we conclude that, [tex]P_4[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]O_2[/tex] is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of [tex]P_4O_{10}[/tex]

From the reaction, we conclude that

As, 5 mole of [tex]O_2[/tex] react to give 1 mole of [tex]P_4O_{10}[/tex]

So, 0.200 moles of [tex]O_2[/tex] react to give [tex]\frac{0.200}{5}=0.04[/tex] moles of [tex]P_4O_{10}[/tex]

Now we have to calculate the mass of [tex]P_4O_{10}[/tex]

[tex]\text{ Mass of }P_4O_{10}=\text{ Moles of }P_4O_{10}\times \text{ Molar mass of }P_4O_{10}[/tex]

[tex]\text{ Mass of }P_4O_{10}=(0.04moles)\times (283.9g/mole)=11.4g[/tex]

Theoretical yield of [tex]P_4O_{10}[/tex] = 11.4 g

Experimental yield of [tex]P_4O_{10}[/tex] = 10.0 g

Now we have to calculate the percent yield of [tex]P_4O_{10}[/tex]

[tex]\% \text{ yield of }P_4O_{10}=\frac{\text{ Experimental yield of }P_4O_{10}}{\text{ Theretical yield of }P_4O_{10}}\times 100[/tex]

[tex]\% \text{ yield of }P_4O_{10}=\frac{10.0g}{11.4g}\times 100=87.7\%[/tex]

Therefore, the percent yield of [tex]P_4O_{10}[/tex] is, 87.7 %