Endothermic and Exothermic Reactions Flashcards
(15 cards)
What happens during a chemical reaction?
Energy is transferred to or from the surroundings.
What is an exothermic reaction?
An exothermic reaction is a chemical reaction that transfers energy to the surroundings, usually feeling hot.
What is an endothermic reaction?
An endothermic reaction is a chemical reaction that absorbs energy from the surroundings, usually feeling cold.
Can you give an example of an exothermic reaction?
Handwarmers are an example of an exothermic reaction as they release heat into their surroundings.
Do exothermic reactions always release heat?
No, sometimes exothermic reactions release energy as light, such as glowsticks.
What happens in an exothermic neutralisation reaction?
When sodium hydroxide solution is mixed with hydrochloric acid, the temperature rises, indicating an exothermic reaction.
What is respiration in terms of chemical reactions?
Respiration is a chemical process that releases energy for organisms to use to stay alive.
What is an endothermic reaction?
An endothermic reaction absorbs energy from the surroundings, causing the surroundings to get colder.
Can you give an example of an endothermic reaction?
Photosynthesis is an endothermic reaction because plant leaves absorb light energy.
What happens in an endothermic reaction with sodium carbonate and ethanoic acid?
When sodium carbonate powder is mixed with ethanoic acid, the temperature falls, indicating an endothermic reaction.
What occurs when ammonium chloride is mixed with barium hydroxide?
The temperature drops to –14°C, indicating an endothermic reaction.
How can exothermic and endothermic reactions be investigated?
They can be investigated using a thermometer in a science lab.
What is important for accurate results in experiments?
Minimising sources of error is crucial for accurate and repeatable results.
What is an outlier in experimental results?
An outlier is a result that is very different from the rest of the measurements, and it is usually best to ignore it.
How can accuracy be improved in experiments?
Accuracy can be improved by obtaining a precise room temperature and using an insulated polystyrene cup.
