Use the experiment described to answer the question.
You will conduct an experiment at home.
Use the following materials:
Clear plastic bottle
150 mL of hot water
Yeast
Sugar
Balloon
Teaspoon
Follow these directions:
Start by pouring three teaspoons of yeast and two teaspoons of sugar into the plastic bottle. Then slowly pour the hot water into the bottle. Stretch the opening of the balloon, and place it over the bottle’s opening. Wait approximately 30 minutes. Observe the balloon inflating as the liquid starts to foam.
How do you know that a chemical change occurred in the experiment?
THE BALLOON INFLATED.
You know that a chemical change occurred in the experiment because the yeast and sugar reacted with the hot water to produce carbon dioxide gas, which caused the balloon to inflate.
A. the yeast mixed with sugar
B. the balloon inflated
C. the hot water warmed the bottle
D. the balloon was stretched over the bottle
Read the answer.
In this experiment, you can determine that a chemical change occurred by observing the inflation of the balloon and the foaming of the liquid inside the bottle. The following explanation will outline the steps to understand why these changes indicate a chemical reaction:
1. Set up the experiment as described, using a clear plastic bottle, hot water, yeast, sugar, a balloon, and a teaspoon.
2. Pour three teaspoons of yeast and two teaspoons of sugar into the plastic bottle.
- The yeast is a living organism that feeds on sugar.
3. Slowly pour the hot water into the bottle.
- Heat helps to activate the yeast.
4. Stretch the opening of the balloon and place it over the bottle's opening, ensuring it is tightly sealed.
- The balloon is used to capture and measure the gas produced during the reaction.
5. Wait approximately 30 minutes and pay attention to any visible changes.
- The reaction needs time to occur and produce noticeable results.
6. Observe the balloon inflating as the liquid starts to foam.
- The inflation of the balloon indicates the production of a gas, most likely carbon dioxide (CO2). The foaming indicates the release of gas bubbles. Both of these changes are signs of a chemical reaction.
So, in essence, the chemical change occurs as the mixture of yeast, sugar, and hot water causes a reaction that produces carbon dioxide gas (CO2), which inflates the balloon and causes the liquid to foam. Therefore, by observing these changes, you can conclude that a chemical reaction has taken place in the experiment.