Mr[MgNO3] = Ar[Mg] + Ar[N] + Ar[O] * 3 = 24. 305 + 14. 0067 + 15. 9994 * 3 = 86. 3099
Mr[Ca(OH)2] = Ar[Ca] + Ar[O] * 2 + Ar[H] * 2 = 40. 078 + 15. 9994 * 2 + 1. 00794 * 2 = 74. 09268
Mr[H2S] = Ar[H] * 2 + Ar[S] = 1. 00794 * 2 + 32. 065 = 34. 08088
Mr[Al2O3] = Ar[Al] * 2 + Ar[O] * 3 = 26. 9815386 * 2 + 15. 9994 * 3 = 101. 9612772