Question

1. a student combines solutions of silver nitrate, agno₃, and sodium chromate, na₂cro₄, and observes that a reddish - brown solid forms. based on this observation, which type of a reaction can the student infer has occurred?

acid - base reaction
precipitation reaction
combustion reaction
decomposition reaction

Explanation:

A precipitation reaction is defined as a reaction where two soluble salts react to form an insoluble solid (precipitate). Here, soluble silver nitrate ($\text{AgNO}_3$) and sodium chromate ($\text{Na}_2\text{CrO}_4$) react to produce a reddish-brown solid (silver chromate, $\text{Ag}_2\text{CrO}_4$), which matches the definition of a precipitation reaction. Acid-base reactions involve proton transfer, combustion reactions require oxygen and produce oxides, and decomposition reactions break down a single compound, none of which fit the observation.

Answer:

precipitation reaction