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.

Answer : The percent yield of is, 87.7 %

Solution : Given,

Moles of = 0.200 mole

Moles of = 0.200 mole

Molar mass of = 283.9 g/mole

First we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

From the balanced reaction we conclude that

As, 5 mole of react with 1 mole of

So, 0.200 moles of react with moles of

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

Now we have to calculate the moles of

From the reaction, we conclude that

As, 5 mole of react to give 1 mole of

So, 0.200 moles of react to give moles of

Now we have to calculate the mass of

Theoretical yield of = 11.4 g

Experimental yield of = 10.0 g

Now we have to calculate the percent yield of

Therefore, the percent yield of is, 87.7 %

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.