A 0.5843-g sample of a plant food preparation was analyzed for its N content by the Kjeldahl

Question:

A 0.5843-g sample of a plant food preparation was analyzed for its N content by the Kjeldahl method, the liberated NH3 being collected in 50.00 mL of 0.1062 MHCl. The excess acid required an 11.89 mL back-titration with 0.0925 M NaOH. Express the results of this analysis in terms of
(a) %N.
(b) %urea, H2NCONH2.
(c) %(NH4)2SO4.
(d) %(NH4)3=PO4.