Q.

9.3 g of aniline is subjected to reaction with excess of acetic anhydride to prepare acetanilide. The mass of acetanilide produced if the reaction is 100% completed is ______ ×10-1 g.

(Given molar mass in g mol-1 N : 14, O : 16
                                                                      C : 12, H : 1)                 [2024]


Ans.

(135)

Moles of aniline (nC6H5NH2)=Mass of anilineMC6H5NH2=9.3 g93 g mol-1=0.1 mol

As aniline is the limiting reagent, moles of acetanilide produced depend upon moles of aniline.

By stoichiometry:

moles of acetanilide = moles of aniline

moles of acetanilide (nC6H5NHCOCH3)=0.1 mol

Mass of acetanilide=nC6H5NHCOCH3×MC6H5NHCOCH3

                                     =0.1 mol×135 g mol-1

                                     =13.5 g=135×10-1 g