Mr[K2CO3] = Ar[K] * 2 + Ar[C] + Ar[O] * 3 = 39. 0983 * 2 + 12. 0107 + 15. 9994 * 3 = 138. 2055
Mr[Zn3(PO4)2] = Ar[Zn] * 3 + Ar[P] * 2 + Ar[O] * 8 = 65. 409 * 3 + 30. 973762 * 2 + 15. 9994 * 8 = 386. 169724
Mr[CuCl2] = Ar[Cu] + Ar[Cl] * 2 = 63. 546 + 35. 453 * 2 = 134. 452
Mr[H2SO4] = Ar[H] * 2 + Ar[S] + Ar[O] * 4 = 1. 00794 * 2 + 32. 065 + 15. 9994 * 4 = 98. 07848
Mr[Pb(OH)2] = Ar[Pb] + Ar[O] * 2 + Ar[H] * 2 = 207. 2 + 15. 9994 * 2 + 1. 00794 * 2 = 241. 21468