Q 24 part (d).


24. Solid ammonium dichromate decomposes as under: 

${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\to {\mathrm{N}}_2+{\mathrm{Cr}}_2{\mathrm{O}}_3+4{\mathrm{H}}_2\mathrm{O}$
If 63 g of ammonium dichromate decomposes, calculate:
(a) The quantity in moles of (NH₄)₂ Cr₂O₇
(b) The quantity in moles of nitrogen formed
(c) The volume of N₂ evolved at STP. 
(d) The loss of mass