Question

endothermic
a reaction in which energy is absorbed by matter
exothermic
a reaction in which energy is released by matter

• endothermic reactions: reactants have ____________ energy than the products.
• exothermic reactions: reactants have ____________ energy than the products.

think pair share & practice

• in a laboratory, a student combines vinegar and baking soda into a beaker. the initial temperature is 28°c and the final temperature, 2 minutes later, is 20°c.

what happened to the heat in the surroundings?
did an endothermic or exothermic reaction occur?

• is this energy diagram representing an endothermic or exothermic reactions? explain!

nearpod quiz score: ____/5

Explanation:

Step1: Recall endothermic - exothermic definitions

Endothermic reactions absorb heat from surroundings, exothermic release heat to surroundings.

Step2: Analyze endothermic reaction energy

In endothermic reactions, reactants have less energy than products as energy is absorbed to form products.

Step3: Analyze exothermic reaction energy

In exothermic reactions, reactants have more energy than products as excess energy is released.

Step4: Analyze vinegar - baking soda reaction

The temperature decreased from 28°C to 20°C. This means the reaction absorbed heat from the surroundings.

Step5: Determine reaction type

Since heat was absorbed from the surroundings, it is an endothermic reaction.

Answer:

• Endothermic Reactions: less
• Exothermic Reactions: more
• What happened to the heat in the surroundings: Heat was absorbed by the reaction from the surroundings.
• Did an endothermic or exothermic reaction occur? Endothermic reaction occurred.
• For the unspecified energy - diagram question: If the energy of products is higher than reactants, it is an endothermic reaction; if the energy of reactants is higher than products, it is an exothermic reaction.