Answer:
Ca(OH)₂ and HCl(aq)
Explanation:
We have the products of a reaction, CaCl₂ and H₂O. Since the products are a salt and water, this is likely to be a neutralization reaction. In such a reaction, an acid and a base react to form a salt and water.
The complete molecular equation is:
Ca(OH)₂ + 2 HCl(aq) → CaCl₂ + 2 H₂O