This reaction involves the following steps:

ZnCl2 (Zinc Chloride) reacts with NaOH (Sodium Hydroxide) to form Zn(OH)2 (Zinc Hydroxide) and NaCl (Sodium Chloride):
ZnCl2 + 2NaOH → Zn(OH)2 + 2NaCl

Zn(OH)2 reacts with excess ZnCl2 to reform ZnCl2:
Zn(OH)2 + 2HCl → ZnCl2 + 2H2O

Finally, the ZnCl2 reacts with excess NaOH to form Na2[Zn(OH)4]:
ZnCl2 + 4NaOH → Na2[Zn(OH)4] + 2NaCl

Overall, the reaction can be summarized as:
ZnCl2 + 6NaOH → Na2[Zn(OH)4] + 2NaCl