Exothermic And Endothermic Reactions

Question 1

Name three endothermic reactions..

Answer 1

Ethanoic acid + sodium carbonate
Electrolysis
Thermal decomposition of calcium carbonate in a furnace.

Question 2

Name three exothermic reactions…

Answer 2

• burning
• neutralisation
• water to calcium oxide

Question 3

Endothermic reactions …. In energy from surroundings to …. Chemical bonds. This causes temperature to…

Answer 3

Takes, break, drop.

Question 4

Exothermic reactions … Heat energy. This occurs when making ……. And causes … Rise.

Answer 4

Give out, chemical bonds, temperature to.

Question 5

Energy released in …. Reactions = energy taken in at … Reactions.

Answer 5

Exothermic, endothermic.

Question 6

Give examples of a reaction that happens with endothermic reactions and one with exothermic.

Answer 6

Endothermic = photosynthesis.
Exothermic = fuels burning or neutralisation.

Question 7

Why is energy management important for exothermic reactions?

Answer 7

If lots of heat is provided this could cause reaction rate to increase making the mixture hotter. This could lead to the products turning into gases, increasing pressure and leading to an explosion. Heat needs to be taken.

Question 8

Why is energy management important in endothermic reactions?

Answer 8

Heat needs to be provided as otherwise the reaction mixture will become too cold, causing the reaction rate to slow and the reactants to freeze, damaging equipment or stopping the process.