How many moles of pcl5 can be produced from 55.0 g of cl2 (and excess p4) ? express your answer to three significant figures and include the appropriate units?

The balanced equation for the reaction is,

P₄ + 10Cl₂ - - - > 4PCl₅

Stoichiometry of Cl₂ to PCl₅ 10:4

The number of Cl₂ moles reacted - 55.0 g / 71 g/mol = 0.77 mol

Cl₂ is the limiting reactant, amount of product formed depends on amount of limiting reactant present.

10 mol of Cl₂ produces - 4 mol of PCl₅

when 0.77 mol of Cl₂ reacts - 4/10 x 0.77 = 0.308 mol

Therefore 0.308 mol of PCl₅ is formed