Question

question 16 of 30
when a substance is added to water, bubbles form. how can you confirm the type of change that took place? how can you confirm the type of change that took place?
a. determining that the gas produced in the reaction was different from the original substance would confirm that a chemical change took place.
b. the formation of bubbles is confirmation that a physical change took place.
c. showing that the total mass of the reactants equaled the total mass of the products would confirm that a physical change took place.
d. the formation of bubbles is confirmation that a chemical change took place.

Explanation:

In a chemical change, new substances are formed. If the gas produced is different from the original substance, it indicates a chemical reaction has occurred. The formation of bubbles alone doesn't confirm the type of change as it could be due to a physical process like dissolution of a gas - in - water under pressure change. The law of conservation of mass applies to both physical and chemical changes, so it can't be used to distinguish between them.

Answer:

A. Determining that the gas produced in the reaction was different from the original substance would confirm that a chemical change took place.