Exothermic and endothermic reactions Flashcards Preview

GCSE Chemistry Unit 2 > Exothermic and endothermic reactions > Flashcards

Flashcards in Exothermic and endothermic reactions Deck (6)
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The forward reaction is exothermic, so the reverse reaction is ________. [1]



Calculate the percentage by mass of nitrogen in ammonia (NH₃). [3]

82 (%)


Suggest one improvement the student could make to the apparatus when investigating the temperature change. [2]

- add a lid...
- ...to reduce / stop heat loss
- use a digital thermometer...
- ...for more accurate data


The reaction to produce magnesium from magnesium oxide is endothermic.
What is meant by an endothermic reaction? [1]

(a reaction which) takes in energy (from the surroundings)


The equation for the reaction is:
2 NaHCO₃(s) → Na₂CO₃(s) + H₂O(g) + CO₂(g)
The cake mixture rises when baked.
Use the equation to suggest why. [1]

gas / carbon dioxide / steam is produced


The same reaction can be reversed to produce sodium hydrogencarbonate from
sodium carbonate.
Na₂CO₃ + H₂O + CO₂ → 2NaHCO₃
Do the reactants need to be heated?
Give a reason for your answer. [1]

- no, because (reaction) is exothermic
- yes, to start the reaction