A.  ${\mathrm{Li}}_2{\mathrm{SO}}_4.\mathrm{Al} {\left({\mathrm{SO}}_4\right)}_3.24{\mathrm{H}}_2\mathrm{O}$

B.  ${\mathrm{K}}_2{\mathrm{SO}}_4.{\mathrm{Al}}_2 {\left({\mathrm{SO}}_4\right)}_3.24{\mathrm{H}}_2\mathrm{O}$

C.  ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4.{\mathrm{Al}}_2 {\left({\mathrm{SO}}_4\right)}_3.24{\mathrm{H}}_2\mathrm{O}$

D.  ${\mathrm{Na}}_2{\mathrm{SO}}_4.{\mathrm{Al}}_2 {\left({\mathrm{SO}}_4\right)}_3.24{\mathrm{H}}_2\mathrm{O}$

A.  $N{a}_{2}S{O}_4.A{l}_2{\left(S{O}_4\right)}_3.24H_{2}O.$

B. $K_{2}S{O}_4.A{l}_2{\left(S{O}_4\right)}_3.24H_{2}O.$

C.  $\left(N{H}_4\right)S{O}_4.A{l}_2{\left(S{O}_4\right)}_3.24H_{2}O.$

D.  $L{i}_{2}S{O}_4.A{l}_2{\left(S{O}_4\right)}_3.24H_{2}O.$

A. $N{a}_{2}S{O}_4.2A{l}_2{(SO}_{}$ ₄ ) 3 . 24 H 2 O . 

B.  $2K_{2}S{O}_4.FeS{O}_4.24H_{2}O.$ 

C.  $NaFe{(SO}_{}$ ₄ ) 2 . 12 H 2 O . 

D.  $K_{2}S{O}_4.A{l}_2{(SO}_{}$ ₄ ) 3 . 24 H 2 O . 

A. 4

B. 5

C. 2

D. 3