The number of moles of cl2 produce will be ??????? If one mole of pcl5 is heated at 250 in a vessel having a capacity of 10dm³.
PCl5 ==> PCl3 + Cl2
Is this 100% reaction or must you use the Keq (which you don't list).
Is this 100% reaction or must you use the Keq (which you don't list).