Co(NO3)2 Co(+2)N(+5)O(-2)
Mr(Co(NO3)2 = 59 + 14*2 + 16*6 = 183
MgSO4 Mg(+2)S(+6)O(-2)
Mr(MgSO4) = 24 + 32 + 16*4 = 120
Co(NO3)2 Co(+2)N(+5)O(-2)
Mr(Co(NO3)2 = 59 + 14*2 + 16*6 = 183
MgSO4 Mg(+2)S(+6)O(-2)
Mr(MgSO4) = 24 + 32 + 16*4 = 120