C7 Flashcards
Draw an exothermic reaction profile?
draw
Draw an endothermic reaction profile?
draw
draw an electrolysis cell?
draw
Advantages of hydrogen fuel cells
- They will produce electricity for as long as you provide hydrogen
- Hydrogen fuel cells do not get less efficient the longer they run
Bond Energy Formula?
energy change = sum of the energy needed to break bonds (reactants) - energy released when new bonds are formed (products)
Characteristics of fuel cells?
- reliable
- efficient
- compact and lightweight
- not very polluting
Disadvantages of hydrogen fuel cells
- Highly Explosive
- They produce a relatively low potential difference or voltage so several are needed together
Electrolysis and photosynthesis is an example of a _____.
endothermic reaction
Example of a endothermic reaction
citric acid + sodium hydrogencarbonate
Example of reactive profile diagram with catalyst
draw
How can rechargeable batteries be recharged?
The chemical reactions can be reversed when an electrical current is applied.
How does the reactivity of the metals link to the potential difference of the metals?
The greater the difference between the reactivity of the metals, the greater the potential difference produced by the cell.
How is a electrochemical cell set up?
1) 2 electrodes which are metals as they must conduct electricity
2) The electrolyte is a liquid that contains ions
3) Wire connecting the 2 electrodes
If the energy change on an energy level diagram is negative, is this an endothermic or exothermic reaction?
Exothermic reactions have a negative energy change because they release/lose energy.
In an ____ reaction, the energy of the reactants is higher than the energy of the products.
exothermic