Chemical Cells and Batteries

How do two electrodes of different metals give pd?

More reactive metal will form ions and release e- more easily

so they become positive and the electrolyte negative; this sets up a charge difference

difference in ability to release e- will cause pd to flow

I will flow if part of a complete circuit

How to increase pd?

• increase difference in reactivity

• increase concentration of electrolyte

• increase SA electrodes

• decrease distance between electrodes

Compare rechargeable and non-rechargeable batteries

• Chemical reactions in rechargeable batteries can be reversed with an external power supply but non-rechargeable cannot

• rechargeable batteries are more environmentally friendly and cost effective as raw materials are conserved

Difference between batteries and electrolysis

Batteries use difference in reactivity to produce pd

Electrolysis uses pd to separate ions