If 5 moles of p4 reacted with 22 moles cl2 according to the above reaction, determine:
a. how many moles pcl3 are produced
b. how many moles of p4 are left in excess after the reaction (if any)
c. how many moles of cl2 are left in excess after the reaction (if any)

Solution:

a) By stoichoimetry If 6 moles of gives 4 mole of , then 22 moles of will give: moles of

b) If 6 moles of reacts with one mole of , then 22 moles of will react : moles of

Moles of  left after the reaction = moles.

c) 0 Moles of , since it is present in less amount it will get completely consumed in the reaction. Hence, it is limiting reagent.

it should be all of them because it asks if you included all of those in your answer

explanation:

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.