Bond Energies and Hydrogen Fuel Cells Flashcards
What do endothermic reactions involve?
Bond breaking.
What do exothermic reactions involve?
Bond forming.
Is energy supplied or released for/by bond forming?
Released.
Is energy supplied or released for/by bond breaking?
Supplied.
How can the energy released by a chemical reaction be measured?
- Measure temperature
- Mix in polystyrene cup
- Measure temperature
What are the problems with energy measurements?
Amount of energy lost to surroundings.
How can the problems with energy measurement be solved?
- Beaker of cotton wool
2. Lid on cup
What is the disadvantage of burning fuels?
It causes climate change.
Why is it expensive to slow down the effects of climate change?
Alternative energy costs money to develop.
Why does the price of crude oil have such a large economic effect?
Everything that’s transported by vehicles will be get more expensive as crude oil does.
What is calorimetry?
Burning fuels and using the flame to heat up water.
In exothermic reactions, is the deltaH positive or negative?
Negative.
In endothermic reactions, is the deltaH positive or negative?
Positive.
What is activation energy?
The minimum energy needed by reacting particles to break their bonds.
How do catalysts affect the activation energy?
They provide a different reaction that has a lower activation energy.
