Hot or Cold? Energy in Reactions

Every reaction either gives out energy or takes it in. Pick a reaction, press Start, and watch the heat. If the flask warms and heat streams out, it is exothermic. If it cools and heat is pulled in, it is endothermic.

Pick a reaction, then press Start Watch the thermometer and the heat arrows Out and warmer, or in and cooler?

Pick a reaction and press Start.

Choose a reaction

The two tags are hidden until you have seen each one happen — try to predict which way the thermometer will go before you press Start.

What happened

Press Start to run the reaction.

Readings

Temperature25 °C

Change0.0 °C

Heat—

Exothermic reactions release energy as heat, so the surroundings warm up. Endothermic reactions absorb it, so the surroundings cool down.