Energy Changes

What word is used to describe a reaction that absorbs energy from the surroundings to feel colder?

• Endothermic

• Exothermic

• Combustion

• Displacement

What kind of reaction is combustion (burning)?

• Exothermic

• Endothermic

What kind of reaction is used in handwarmers?

• Exothermic

• Endothermic

Respiration is a chemical reaction that occurs within the cells of living organisms to release energy. Which word describes respiration?

• Exothermic

• Endothermic

When copper carbonate is heated, it absorbs energy and breaks down into copper oxide and carbon dioxide. What kind of reaction is this?

• Endothermic

• Exothermic

Ammonium chloride and barium hydroxide are mixed together. At the start of the reaction the temperature is 20°C and this goes down to 3°C. Which statement is correct?

• It is endothermic

• It is exothermic

• It will explode

• It hasn't worked

Small pieces of calcium metal are added to some cold water. At the end of the reaction, the temperature has gone up to 47°C. Which word describes this reaction?

• Exothermic

• Endothermic

• Colourless

• Fizzes

What piece of equipment is useful for investigating exothermic and endothermic reactions in the laboratory?

• Thermometer

• Beaker

• Test tube

• Weighing balance

Hand warmers use ​ (a)   reactions to ​ (b)   the temperature of the surroundings to feel warm. Cold packs use ​ (c)   reactions to ​ (d)   the temperature of the surroundings to feel ​ (e)  

• exothermic
• increase
• endothermic
• decrease
• cold
• warm
• keep
• explosive
• long

Exothermic reactions ​ (a)   energy to ​ (b)   the temperature of the surroundings.

• release
• increase
• absorb
• decrease
• keep