Question

Sodium bicarbonate (a white powder) is combined with acetic acid (a clear liquid).

Which of the following provides evidence that proves a chemical reaction took place?

A. The sodium bicarbonate floated to the top.
B. The resulting mixture produced carbon dioxide gas.
C. The temperature of the resulting mixture decreases.
D. No change was observed.

Answer 1

The evidence that proves a chemical reaction took place when sodium bicarbonate is combined with acetic acid is the production of carbon dioxide gas.

Step-by-step explanation:

The evidence that proves a chemical reaction took place when sodium bicarbonate is combined with acetic acid is option B: The resulting mixture produces carbon dioxide gas.

When sodium bicarbonate reacts with acetic acid, it undergoes a chemical reaction known as a neutralization reaction. Bicarbonate ions (HCO3-) from sodium bicarbonate combine with hydrogen ions (H+) from acetic acid to form carbonic acid (H2CO3). Carbonic acid then decomposes into water (H2O) and carbon dioxide (CO2) gas.

This production of carbon dioxide gas is evidence of a chemical reaction taking place because it is a new substance being formed as a result of the reaction. The other options, such as A, C, and D, do not provide evidence of a chemical reaction.