Endo And Exothermic Reactions Flashcards
(8 cards)
What are the most common exothermic reactions?
Combustion,neutralisation, oxidation
On a reaction profile diagram, how is activation energy shown?
A dotted line between the reactants and the top of the curve
In order to have an endothermic reaction what do you often need to supply?
Heat e.g Bunsen burner
What are examples of endothermic reactions?
- thermal decomposition
- reaction of citric acid with sodium hydrocarbonate
- electrolysis
What is the graph to show exo + endothermic reactions called and what is on the x and y axis?
Graph name: energy profile graphs
X axis - progress of reaction
Y axis - energy
What is activation energy?
Minimum amount of energy for atoms to collide with one another in order to react
What is the method of the practical involving sodium hydroxide + hydrochloric acid? What is the conclusion?
- place 25cm3 of sodium hydroxide solution into calorimeter (digital thermometer)
- measure and record temp of solution
- add 5cm3 of dilute hydrochloric acid and stir
- measure and record highest temp reached by mixture
- repeat previous steps, increasing amount of acid added each time by 5cm3
Conclusion: larger the difference in temperature, the more energy absorbed or released
What is a calorimeter?
Digital thermometer
