Chemical Reactions and Energy

Why does dissolving salt in water feel cooler to the touch?

• It releases energy as heat.

• It absorbs energy from the surroundings.

• Salt increases the water’s temperature.

• The salt particles heat up rapidly.

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How does this process follow the law of conservation of energy?

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When you dissolve salt in water, the temperature of the water slightly decreases. What type of energy change is this, and why does it happen?

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This image shows a

• chemical reaction

• physical change

• musical change

• all of these answers are correct

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When energy like heat and light are given off in a chemical reaction it is called

• exothermic

• endothermic

• eccentric

• ectomorphic

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When energy is absorbed and taken in during a chemical reaction it is called

• exothermic

• endothermic

• eccentric

• ectomorphic

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Signs of a chemical change could be:

• a change in energy (temperature, light, sound)

• a precipitate forms (a solid forms from 2 liquids)

• formation of gas (bubbles)

• shocking change in color

• all of these answers are signs of chemical change

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In an exothermic reaction, heat is ...

• taken in

• given out

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What type of reaction occurs in a hand warmer?

• exothermic

• endothermic

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_____ reactions usually feel hot!

• endothermic

• exothermic

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