2NaCl=эле-з 2Na+Cl2
117г 46г
1)117*46/117=46г
2)10/46*100=21,7%
Cuso4+bacl=cucl2+baso4 (осадок)
Cu^2+ +so4^2- +ba^2+ +2cl^- = cu^2+ +2cl^2- + baso4
Ba^2+ + so4^2- = baso4
Mgohcl+hcl=mgcl2+h2o
Mg^2+ +oh^- + cl^- + h^+ + cl^- = md^2+ +2cl^- +h2o
H^+ + oh^- = h2o