KMnO4:
K - 39.10
Mn - 54.94
O - 16.00 $4atoms$

Molar mass = 39.10 + 54.94 + 16.00$4$ = 158.03 g/mol

ZnCl2:
Zn - 65.38
Cl - 35.45 $2atoms$

Molar mass = 65.38 + 35.45$2$ = 136.28 g/mol

LiOH:
Li - 6.94
O - 16.00
H - 1.01

Molar mass = 6.94 + 16.00 + 1.01 = 23.95 g/mol