Мr(H2SO4)= 2*Ar(H)+Ar(S)+4Ar(O)=2*1а.е.м.+32а.е.м.+4*16а.е.м.=98 а.е.м.
Mr(Fe2O3)= 2*Ar(Fe)+3*Ar(O)=2*56а.е.м.+3*16а.е.м.=160 а.е.м.
Mr(Mg(OH)2)=Ar(Mg)+2*Ar(H)+2*Ar(O)=24а.е.м.+2а.е.м.+ 32а.е.м.=58 а.е.м.
Mr(Ca3(PO4)2)= 3*Ar(Ca)+2*Ar(P)+8*Ar(O)=120а.е.м.+62а.е.м.+ 128а.е.м.=310 а.е.м.
Mr(Zn(AIO2)2)= Ar(Zn)+2*Ar(Al)+4*Ar(O)=65а.е.м.+54а.е.м.+ 64а.е.м.=183 а.е.м.
Mr(Cd(N3)2)= Ar(Cd)+6Ar(N)=112а.е.м.+6*14=196 а.е.м.
Mr(C14H10)= 14*Ar(Mg)+10*Ar(H)=14*12а.е.м.+10*1а.е.м.=178 а.е.м.
Mr(KCIO3)=Ar(K)+Ar(Cl)+3*Ar(O)=39а.е.м.+35,5а.е.м.+ 3*16а.е.м.=122,5 а.е.м.
Mr(NaBr)=Ar(Na)+Ar(Br)=23а.е.м.+80 а.е.м.=103 а.е.м.
Мr(H2SO4)= 2*Ar(H)+Ar(S)+4Ar(O)=2*1а.е.м.+32а.е.м.+4*16а.е.м.=98 а.е.м.
Mr(Fe2O3)= 2*Ar(Fe)+3*Ar(O)=2*56а.е.м.+3*16а.е.м.=160 а.е.м.
Mr(Mg(OH)2)=Ar(Mg)+2*Ar(H)+2*Ar(O)=24а.е.м.+2а.е.м.+ 32а.е.м.=58 а.е.м.
Mr(Ca3(PO4)2)= 3*Ar(Ca)+2*Ar(P)+8*Ar(O)=120а.е.м.+62а.е.м.+ 128а.е.м.=310 а.е.м.
Mr(Zn(AIO2)2)= Ar(Zn)+2*Ar(Al)+4*Ar(O)=65а.е.м.+54а.е.м.+ 64а.е.м.=183 а.е.м.
Mr(Cd(N3)2)= Ar(Cd)+6Ar(N)=112а.е.м.+6*14=196 а.е.м.
Mr(C14H10)= 14*Ar(Mg)+10*Ar(H)=14*12а.е.м.+10*1а.е.м.=178 а.е.м.
Mr(KCIO3)=Ar(K)+Ar(Cl)+3*Ar(O)=39а.е.м.+35,5а.е.м.+ 3*16а.е.м.=122,5 а.е.м.
Mr(NaBr)=Ar(Na)+Ar(Br)=23а.е.м.+80 а.е.м.=103 а.е.м.
m(HNO3)раствора=V*p=281*1.031=289.711
m(HNO3)вещества=m(HNO3)раствора*w=289.711*0.063=18.25
n(HNO3)=m/M=18.25/63=0.3
n(Al(NO3)3)=n(HNO3)/3=0.3/3=0.1
m(Al(NO3)3)=n*M=0.1*213=21.3
n(Al2O3)=n(HNO3)/6=0.3/6=0.05
m(Al2O3)=n*M=0.05*102=5.1
mраствора=m(HNO3)раствора+m(Al2O3)=289.711+5.1=294.8
w(Al(NO3)3)=m(Al(NO3)3)/mраствора=21.3/294.8=0.072 или 7,2%