[Suzume]

Can you help me with this please ? I want to ask about how to diagram an electrochemical cell when the diagram is provided. For example, drawing a cell provided that:

1. Pt|H2(g)|H+(aq)||H+ (aq)|O2(g)|Pt
I have no idea about a cell containing liquid and gas at the same time. Does this mean that this cell will have no salt bridge and gas will be provided externally?

2. Pt|I2(s)|I-(aq)||SO4 2- (aq),H3O+|PbO2(s)|PbSO4 (s)|Pt
Can you give me the principles of this construction. Thank you very much.

[Borek]

1. Pt|H2(g)|H+(aq)||H+ (aq)|O2(g)|Pt
I have no idea about a cell containing liquid and gas at the same time. Does this mean that this cell will have no salt bridge and gas will be provided externally?

There is a salt bridge between both half cells. Each half cell contains a Pt electrode submerged in water, and you are blowing the gas into the solution (usually from the bottom, so that bubbles going up pass close the electrode to agitate the solution).

2. Pt|I2(s)|I-(aq)||SO4 2- (aq),H3O+|PbO2(s)|PbSO4 (s)|Pt
Can you give me the principles of this construction. Thank you very much.

Basically electrodes are stick into the solid and everything is covered with the solution.

[Suzume]

Thanks for your help so far, but I'm still lost at this :

 Pt|I2(s)|I-(aq)||SO4 2- (aq),H3O+|PbO2(s)|PbSO4 (s)|Pt

I really don't know how to draw a cell with this diagram. I mean, I know that there are two Pt electrodes, and there's a salt bridge, but why are so many things happen in between? What is actually happening? If you could draw a cell with this, how would you construct it ?