
Actually Welcome to the concept of Ions .
If we see the reaction.
H2SO4 ==> 2H+ + (SO4)2-
Here you can see, H+ ( Hydrogen ions) and (SO4) 2- ( sulphate ions) are the ions when the H2SO4 is dissolved in water.
I believe it occurs along the plates edge.
NaOH + HNO₃ --------> NaNO₃ + H₂O
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NaNO₃ - sodium nitrate