ɪnðə fˈɜːst stˈɛp, lˈænθænəm ˈɑːksaɪd ɪz hˈiːɾᵻd wɪð æmˈoʊniəm klˈoːɹaɪd tə pɹədˈuːs ðɪ æmˈoʊniəm sˈɔlt ʌvðə pˈɛntɐklˌoːɹaɪd:
In the first step, lanthanum oxide is heated with ammonium chloride to produce the ammonium salt of the pentachloride: