Energy changes

Question 1

What is the difference between exothermic and endothermic with examples

Answer 1

Exothermic - a reaction where energy is released to the surroundings, e.g. combustion and neutralisation
Endothermic - a reaction where energy is absorbed from the surroundings, e.g. thermal decomposition, instant ice packs

Question 2

Required practical : Temperature changes in reacting solutions

What is the method

Answer 2

Place the polystyrene cup inside the glass beaker
Measure 25cm³ of each liquid
Pour one into a cup
Record temperature
Add 5cm³ each time and repeat

Question 3

Required practical : Temperature changes in reacting solutions

What is the independent, dependent and control variables

Answer 3

Independent - liquids you are pouring
Dependent - temperature of liquids
Control - amount of liquid poured, polystyrene cup, thermometer