Energy Changes Flashcards
1
Q
Exothermic reaction
A
Where heat is given off
2
Q
In endothermic reaction
A
Heat is taken in
3
Q
Practical for measuring energy transfer
A
Put 25 cm3 of 0.25 mil:dm of hydrochloric acid and sodium hydroxide in deprecate beakers
Place the beaker in a 25°c water bath
When they are both the same temp add hci followed by NaOH to a polystyrene cup with a lid
Measure and record temp every 30 seconds and record highest temp
Repeat steps with a 0.5 and 1 concentration
4
Q
Reversible reaction
A
Some reactions go backwards
5
Q
Why does an exothermic reaction happen
A
Because the reaction requires less energy to break bonds than energy given off to form bonds
6
Q
Why is a reaction endothermic
A
Because more energy is needed to break bonds than energy given off forming them
