what kind of chemical reaction is 2Na + I2 → 2NaI Classifying Chemical Reactions – Identify the following reactions as synthesis (S), decomposition (D), single-replacement (SR), double-replacement (DR), acid-base (AB) or combustion (C).

Synthesis(S)

Explanation:

 The reaction expression is given as:

        2Na   +   I₂   →    2NaI

 This reaction is a synthesis reaction or combination reaction.

A synthesis reaction is one in which a single product is formed from the combination of two or more reactants.

The combination of two elements to form a compound also falls into this category.

So, the production of NaI is a synthesis reaction.

the correct answer is:

a. formation of precipitation