When the weather starts to cool down, some people in the Midwest like to toast marshmallows over a fire to make a dessert sandwich called a s'more. A marshmallow was toasted at a constant temperature in a laboratory. Use the gif and table below to answer the following questions.

Question

Before (Mass) - 25.21 g (odor) - slight sweet smell (temperature) - 23 degrees Celsius (texture) squishy
After (mass) - 23.78 g (odor) smell of burned sugar and sweetness (temperature) 105 degrees celsius (texture)crumbly with a liquid center
CLAIM
is toasting a marshmallow a chemical or physical change?
A. toasting a marshmallow is a chemical change. B. toasting a marshmallow is not a chemical change. It is only a physical change. C. toasting a marshmallow is not a chemical or physical change.

Answer 1

A. toasting a marshmallow is a chemical change.

The evidence supporting this claim includes the following observations:

1. Odor Change: The initial slight sweet smell of the marshmallow changes to a smell of burned sugar and sweetness, indicating that new substances might be forming during toasting.

2. Mass Change: The marshmallow's mass decreases from 25.21 g to 23.78 g, suggesting that some components (water and gases) were released, typical of a chemical change where new substances are formed and some material is lost.

3. Texture Change: The texture transitions from squishy to crumbly with a liquid center, indicating a change in structure and possibly the formation of new compounds as the sugars and other ingredients caramelize and alter during the toasting process.

4. Temperature Increase: The temperature rises significantly from 23 degrees Celsius to 105 degrees Celsius, which indicates that a physical change (like melting) is occurring alongside the chemical changes.

Together, these points suggest that toasting a marshmallow involves chemical reactions that change its composition, making it a chemical change.