Question

If 5 moles of P4 reacted with 22 moles Cl2 according to the above reaction, determine:

Answer 1

Solution:

$P_4+6Cl_2\rightarrow 4PCl_3$

a) By stoichoimetry If 6 moles of $Cl_2$ gives 4 mole of $PCl_3$ , then 22 moles of $Cl_2$ will give: $\frac{4}{6}\times 22=\frac{44}{3}=14.66$ moles of $PCl_3$

b) If 6 moles of $Cl_2$ reacts with one mole of $P_4$ , then 22 moles of $Cl_2$ will react : $\frac{1}{6}\times 22=\frac{11}{3}=3.66$ moles of $P_4$

Moles of $P_4$  left after the reaction = $5-3.66=\frac{4}{3}=1.34$ moles.

c) 0 Moles of $Cl_2$ , since it is present in less amount it will get completely consumed in the reaction. Hence, it is limiting reagent.