Sally is doing an experiment in chemistry class where she mixes two substances together. When the tow substances react, she notices that the beaker feels cold. What conclusion can Sally draw about this chemical reaction?
a
The two substances did not react
b
It is an endothermic reaction
c
It is an exothermic reaction
d
She cannot draw conclusions based on this information
b. It is an endothermic reaction
To determine the conclusion about this chemical reaction, we need to understand the concepts of endothermic and exothermic reactions. An endothermic reaction is a chemical reaction that absorbs heat from its surroundings, causing the temperature of the surroundings to decrease. On the other hand, an exothermic reaction is a chemical reaction that releases heat to its surroundings, causing the temperature of the surroundings to increase.
In this scenario, Sally notices that the beaker feels cold after mixing the two substances together. This indicates that heat is being absorbed from the surroundings into the reaction, causing a decrease in temperature. Therefore, Sally can draw the conclusion that it is an endothermic reaction (option b).
To answer such questions in general, you can determine the conclusion of a chemical reaction by observing any changes in temperature, light, gas production, color, or any other physical or chemical properties. By understanding the concepts and properties associated with different chemical reactions, you can make an informed conclusion.