Chad's electrolysis example

[bigbutrealdreams]

Hi guys, hopefully you can understand my handwriting.

This example is from Chad's video. He chose two reactions (that I underlined in pink), but why did he choose those two?

Thanks =)

 

[BeaverLover]

Those are the products because its "easier" to form due to a lower voltage required

 

[gooperwooper]

in aqueous electrolysis you take into account water as well. water also has a redox potential. So if you look at a redox table like this one: http://4.bp.blogspot.com/_1o3LAWhybpQ/TRLzpnHH5yI/AAAAAAAAAAw/3yRE84ZtmkI/s1600/Picture3.png

you can see that water can be reduced and can also be formed through oxidation. reduction happens at the cathode, so for 1 you compare the reduction potential of Na versus the reduction potential of water. Whichever voltage is higher is easier to form, so that would be the reaction that actually occurs.