Question

A student made the table below to record his observations when mixing baking soda and vinegar in a beaker

The best evidence for the formation of a new substance is the observation of the —
A.
solid settling.


B.
solid disappearing.


C.
liquid remaining clear.


D.
bubbles forming.

Answer 1

D

Step-by-step explanation:

A chemical reaction is a process in which substances undergo a chemical change to form a different

substance. Mixing baking soda and vinegar will create a chemical reaction because one is an acid

and the other a base. Baking soda is a basic compound called sodium bicarbonate while vinegar is a

diluted solution that contains acetic acid (95% water, 5% acetic acid).

There are five signs that indicate a chemical reaction has occurred: odor, energy change, gas

bubbles, precipitate formation, and color change. When any of these changes occur, the reaction is

irreversible and cannot be undone. The reaction occurs once the vinegar is added to the baking

soda. In this reaction, evidence of a chemical reaction is the formation of carbon dioxide gas and gas

bubbles.

There are two separate types of reactions taking place when mixing baking soda and vinegar. The

first is called an acid-base reaction. When the two substances are mixed together, hydrogen ions in

the vinegar react with the sodium and bicarbonate ions in the baking soda. This initial reaction

results in two new chemicals: carbonic acid and sodium acetate.