During the preparation of NH_3 in Haber's process, the promoter(s) used is / are -

Correct answer: (B) Mo; (C) Mix of Al_2 O_3 and K_2 O. Mo was used as promoter earlier. Now K_2 O and Al_2 O_3 are used as promoter.

Q37 / 155 · WBJEE 2022 · Chemistry

During the preparation of $\mathrm{NH}_3$ in Haber's process, the promoter(s) used is / are -

A
$\mathrm{PtO}_2$
Correct answer
B
Mo
Correct answer
C
Mix of $\mathrm{Al}_2 \mathrm{O}_3$ and $\mathrm{K}_2 \mathrm{O}$
D
Fe and Mn

Mo was used as promoter earlier. Now $\mathrm{K}_2 \mathrm{O}$ and $\mathrm{Al}_2 \mathrm{O}_3$ are used as promoter.

Hence, the correct answer is options: 'B', 'C'.