Topic 5- Chemical cells

Question 1

What do chemical cells produce?

Answer 1

A voltage/ potential difference

Question 2

How do chemical cells produce a voltage?

Answer 2

1)Place two metals in electrolyte of different reactivity
2) More reactive metal looses electrons more quickly which travel to the other metal
3) Cuases a voltage and a current
4) Higher difference between reactivty= higher voltage

If more reactive metal is second voltage = positive

Question 3

When does the chemical cell stop working?

Answer 3

When one reactant is used up

Question 4

What happens in a hydrogen-oxygen cell?

electrochemical cell

Answer 4

-Hydrogen looses electron and moves through anode to cathode (other way round in this)
-Cathode recieves electrons through wire = negative… positve hydrogen is attracted.

-React with oxygen at cathode to make water + heat out through outlet

Description:
inlet, Anode compartement, anode
Electrolyte
Cathode, cathode compartement, inlet + outlet

Question 5

What are the posistives for chemical fuel cells?

Answer 5

-Only produce water
-Keep producing fuel as long as reactants

Question 6

What are the negatives for chemical fuel cells?

Answer 6

-Hydrogen has to be made (expensive + uses fossil fuels)
-Hydrogen is hard to store (takes up space + flammable)

Question 7

How to make a stronger cell?

Answer 7

-Larger potential difference
-Use metals with greater difference in reactivity
-Or make battery by adding another cell in series (add both volts together)

Question 8

Why do cells stop working?

Answer 8

-reactants run out and reaction stops

Question 9

What is a battery?

Answer 9

-More than one cell connected in series
-Creates larger potential difference
-Add their potential differences together

Question 10

How can we recharge batteries?

Answer 10

-Some batteries use reversable reactions
-Reverse these to recharge