C-07-Q111mediumsingle_mcqThe formula of potash alum is—aKAl(SO4)2KAl(SO_4)_2KAl(SO4)2bK2SO4⋅Al2(SO4)3⋅24H2OK_2SO_4 \cdot Al_2(SO_4)_3 \cdot 24H_2OK2SO4⋅AlcAl2(SO4)3Al_2(SO_4)_3Al2(SO4)3dK2SO4K_2SO_4K2SO4