3

Question

When baking soda is combined with vinegar, a chemical reaction occurs. The reactants and products are shown in the table below.

Reactants Products
Baking soda (solid) Sodium acetate (solid)
Vinegar (liquid) Water (liquid)
Carbon dioxide (gas)
Imagine that you combine 100 grams of baking soda and 50 grams of vinegar in an open beaker. After the reaction occurs, the contents of the beaker will have a mass less than 150 grams. Why?

A
The beaker absorbed some of the mass

B
Some of the products are gases that escape into the air

C
The reaction is incomplete and some reactants are left over

D
The reaction created new matter that has less mass
4
Does the reaction in Question 3 follow the law of conservation of mass? Why or why not?

Answer 1

Question 3: The correct answer is B. Some of the products are gases that escape into the air. During the reaction between baking soda (sodium bicarbonate) and vinegar (acetic acid), carbon dioxide gas is produced. If the reaction takes place in an open beaker, some of this carbon dioxide gas will escape into the atmosphere, resulting in a final mass that is less than the total initial mass of the reactants.

Question 4: Yes, the reaction follows the law of conservation of mass. The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. In this case, while the mass of the remaining substances in the beaker is less than the initial mass of the reactants due to the escape of carbon dioxide gas, the total mass of all products (including the gas that escaped) is equal to the mass of the initial reactants. Therefore, the total mass before and after the reaction remains unchanged when considering all substances involved.