Chlorine (Cl2) is a highly reactive and corrosive gas. When it reacts with hot, concentrated sodium hydroxide (NaOH), several products can be formed. Let's examine the possible products and understand why options A and C are correct.

1. Sodium chloride (NaCl):
Chlorine can react with sodium hydroxide to form sodium chloride, which is a common salt. This reaction is represented by the following equation:
Cl2 + 2NaOH → NaCl + NaClO + H2O
In this reaction, one molecule of chlorine reacts with two molecules of sodium hydroxide to produce one molecule of sodium chloride, one molecule of sodium hypochlorite (NaClO), and water (H2O). Therefore, option A (NaCl) is correct.

2. Sodium hypochlorite (NaClO):
Chlorine can also react with sodium hydroxide to form sodium hypochlorite, which is a strong oxidizing agent commonly used in household bleach. The reaction can be represented as follows:
Cl2 + 2NaOH → NaCl + NaClO + H2O
One molecule of chlorine reacts with two molecules of sodium hydroxide to produce one molecule of sodium chloride, one molecule of sodium hypochlorite, and water. Therefore, option C (NaClO) is correct.

3. Sodium chlorate (NaClO3):
Sodium chlorate is not a product of the reaction between chlorine and sodium hydroxide. It is formed through a different process, typically involving the electrolysis of sodium chloride in the presence of a strong oxidizing agent.

4. Hydrochloric acid (HCl):
Hydrochloric acid is not a product of the reaction between chlorine and sodium hydroxide. When chlorine reacts with water, it produces hydrochloric acid and hypochlorous acid. However, in the presence of sodium hydroxide, the reaction favors the formation of sodium chloride and sodium hypochlorite rather than hydrochloric acid.

In conclusion, when chlorine reacts with hot, concentrated sodium hydroxide, the products formed are sodium chloride (NaCl) and sodium hypochlorite (NaClO). Therefore, the correct options are A and C.