Which formula can be used to calculate the theoretical yield?
a) actual yield + percent yield.
b)amount of reactants + amount of products
yield = percent yield) * 100
of reactant = amount of product) x 100

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf   

We can't until we know what we are working with or on