ENDO & EXO Thermic Flashcards
Exothermic means?
Heat is given out
What transfer of energy happens during an exothermic reaction?
Energy is tranferred to the surroundings and the temperature of the surroundings increases.
Endothermic means?
Heat is taken in
What happens to energy during endothermic reactions?
Energy and the temperature of the surroundings decreases.
Combustion reactions are classed as endothermic or exothermic?
Exothermic
Many oxidation reactions are classed as endothermic or exothermic?
Exothermic
Hand warmers would be classed as endothermic or exothermic?
Exothermic
Thermal decomposition is classed as endothermic or exothermic?
Endothermic
Ice packs are classed as endothermic or exothermic?
Endothermic
What are the 3 requirements of the fire triange?
Heat
Oxygen
Fuel
In the endothermic process, bonds are?
Broken
In the exothermic process, bonds are?
Formed
What piece of apparatus is used to measure temperature changes?
Thermometer
What term is given to a reaction which transfers heat energy to the surroundings?
Exothermic
When barium hydroxide and ammonium chloride react, the temperature of the mixture decreases. What kind of reaction is this?
Endothermic
Which of the following should be used to contain the solution when investigating an energy change?
- A polystyrene cup
- A glass beaker
- A measuring cylinder
A polystyrene cup
A polystyrene cup should be used because it insulates the contents from losing or gaining heat from the surroundings. A measuring cylinder is useful for measuring the volumes of liquids.
If the energy change on an energy level diagram is negative, what does this tell you about the reaction?
It is exothermic
Exothermic reactions have a negative energy change on an energy level diagram. Endothermic changes have a positive energy change.
On a reaction profile, what does the height of the hump represent?
The activation energy
Which of these is an endothermic reaction?
- Combustion
- Thermal decomposition
- Oxidation of magnesium
Thermal decomposition
What can you deduce from the reaction profile below?
- The reaction is endothermic
- A catalyst is present
- More energy is released than absorbed
The reaction is endothermic
This reaction profile shows an endothermic reaction. In an endothermic reaction, more heat is absorbed than released.
When calcium reacts with water, the temperature changes from 18°C to 39°C. Is this endothermic or exothermic?
Exothermic
If a reaction releases more energy when new bonds are made than the amount of energy absorbed to break bonds in the reactants, which statement is true? - Higher
- It is endothermic
- It is exothermic
- It is very slow
It is Exothermic
An exothermic reaction releases more energy when new bonds are made than the amount of energy which was absorbed to break the bonds in the reactants.
