Verified answer

Mr(Co(NH3)4(NO2)Cl)NO3)=59+4×14+12+14+16×2+35,5+14+16×3=270,5

w(Co)=59/270,5×100%=21,8%

w(N)=14×6/270,5×100%=31%

w(H)=12/270,5×100%=

4,44%

w(O)=16×5/270,5×100%=29,57%

w(Cl)=35,5/270,5×100%=13,12%