Answer:
The answer is chemical reaction- gas produced.
Step-by-step explanation:
The complete question is:
"The baking soda looked like it dissolved in the vinegar. Sarah and Connor watched as the balloon expanded and filled with a gas. Was this a physical or chemical reaction and why?
A) chemical - gas produced
B) physical - water bottle got hot
C) physical - baking soda dissolved
D) chemical - baking soda disappeared"
A chemical reaction is a process by which one or more substances, called reactants, are transformed into one or more other substances with different properties, called products.
That is, in a chemical reaction, the bonds between the atoms that form the reactants are broken, reorganizing and forming new bonds, thus giving rise to one or more substances different from the initial ones.
Some indications of a chemical change are:
- An unexpected color change indicates the formation of new substances when a chemical process takes place.
- The appearance of precipitates in a solution indicates the formation of a new solid substance that is insoluble and, therefore, deposits at the bottom.
- Gas evolution: This is evident when spontaneous gas evolution occurs when mixing the reagents. This is what happens when acetic acid (vinegar) is added to solid sodium bicarbonate. Carbon dioxide is produced in the form of bubbles, indicating the chemical reaction.
- Sudden variations in temperature are also indicators of the presence of a chemical change, due to the energy differences between the reagents and the products.
So, the answer is chemical reaction- gas produced.